Home/Chain Registry/Block #2,849,576

Block #2,849,576

TWNLength 12★★★★☆

Bi-Twin Chain · Discovered 9/21/2018, 6:30:21 PM · Difficulty 11.7310 · 3,995,611 confirmations

TWN
Bi-Twin Chain

Interleaved pairs of primes that differ by 2, forming twin prime pairs at each level.

Block Header
Block Hash
f16b0699030846cc514150bcecc59700bc32168642880ed46ea960fc601ce97f

Difficulty

11.731045

Transactions

16

Size

3.36 KB

Version

2

Bits

0bbb25c8

Nonce

31,907,354

Timestamp

9/21/2018, 6:30:21 PM

Confirmations

3,995,611

Merkle Root

d085d7dc07983209045b460478c87dc0acb1921e3b6b9cc2b900497465b8238c
Prime Chain Origin

This is the prime chain origin stored in the block header. It is a composite number (not prime itself) — it equals the first prime in the chain multiplied by a primorial. The origin anchors the entire chain to this specific block.

1.144 × 10⁹⁷(98-digit number)
11442332618866692145…51896276630263808000
Discovered Prime Numbers
Lower: 2^k × origin − 1 | Upper: 2^k × origin + 1

These are the actual prime numbers discovered by this block, computed using the verified Primecoin formula. Each number has been independently confirmed to pass the Fermat primality test. Use the FactorDB links to verify any number independently.

Level 0 — Twin Prime Pair (origin ± 1)
origin − 1
1.144 × 10⁹⁷(98-digit number)
11442332618866692145…51896276630263807999
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
1.144 × 10⁹⁷(98-digit number)
11442332618866692145…51896276630263808001
Verify on FactorDB ↗Wolfram Alpha ↗
Difference: origin + 1 − origin − 1 = 2 (twin primes ✓)
Level 1 — Twin Prime Pair (2^1 × origin ± 1)
2^1 × origin − 1
2.288 × 10⁹⁷(98-digit number)
22884665237733384290…03792553260527615999
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
2.288 × 10⁹⁷(98-digit number)
22884665237733384290…03792553260527616001
Verify on FactorDB ↗Wolfram Alpha ↗
Difference: 2^1 × origin + 1 − 2^1 × origin − 1 = 2 (twin primes ✓)
Level 2 — Twin Prime Pair (2^2 × origin ± 1)
2^2 × origin − 1
4.576 × 10⁹⁷(98-digit number)
45769330475466768581…07585106521055231999
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
4.576 × 10⁹⁷(98-digit number)
45769330475466768581…07585106521055232001
Verify on FactorDB ↗Wolfram Alpha ↗
Difference: 2^2 × origin + 1 − 2^2 × origin − 1 = 2 (twin primes ✓)
Level 3 — Twin Prime Pair (2^3 × origin ± 1)
2^3 × origin − 1
9.153 × 10⁹⁷(98-digit number)
91538660950933537162…15170213042110463999
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
9.153 × 10⁹⁷(98-digit number)
91538660950933537162…15170213042110464001
Verify on FactorDB ↗Wolfram Alpha ↗
Difference: 2^3 × origin + 1 − 2^3 × origin − 1 = 2 (twin primes ✓)
Level 4 — Twin Prime Pair (2^4 × origin ± 1)
2^4 × origin − 1
1.830 × 10⁹⁸(99-digit number)
18307732190186707432…30340426084220927999
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
1.830 × 10⁹⁸(99-digit number)
18307732190186707432…30340426084220928001
Verify on FactorDB ↗Wolfram Alpha ↗
Difference: 2^4 × origin + 1 − 2^4 × origin − 1 = 2 (twin primes ✓)
Level 5 — Twin Prime Pair (2^5 × origin ± 1)
2^5 × origin − 1
3.661 × 10⁹⁸(99-digit number)
36615464380373414865…60680852168441855999
Verify on FactorDB ↗Wolfram Alpha ↗
2^5 × origin + 1
3.661 × 10⁹⁸(99-digit number)
36615464380373414865…60680852168441856001
Verify on FactorDB ↗Wolfram Alpha ↗
Difference: 2^5 × origin + 1 − 2^5 × origin − 1 = 2 (twin primes ✓)

What this block proved

The miner who found this block proved the existence of 12 consecutive prime numbers forming a Bi-Twin Chain. The prime chain origin — the large number shown above — anchors the chain and is divisible by a primorial (the product of small primes), cryptographically tying these prime numbers to this specific block.

View full Prime Chain Discovery page →
★★★★☆
Rarity
ExceptionalChain length 12
How Primecoin's Proof-of-Work Constructs These Primes

Primecoin stores a value called the prime chain origin in each block. The miner found a large integer such that when divided by a primorial (the product of small primes: 2 × 3 × 5 × 7 × …), the result is the first prime in the chain. The origin is deliberately divisible by this primorial — that divisibility is part of the proof.

Prime Chain Origin = First Prime × Primorial (2·3·5·7·11·…)
Source: Primecoin prime.cpp — CheckPrimeProofOfWork()

This is why the origin has many small prime factors — those factors are the primorial divisor. The chain then extends from the first prime using the TWN formula:

TWN: twin pairs (p, p+2) where p = origin/primorial − 1 and p+2 = origin/primorial + 1
Verify on a Primecoin Node

Anyone running a Primecoin node can independently verify this block using the following RPC commands. Run these from the primecoin-cli command line or via the debug console in the Primecoin wallet.

1. Get block hash by height
getblockhash 2849576

Returns the block hash for a given block height. Use this to confirm the hash shown above matches the chain.

2. Get full block data
getblock f16b0699030846cc514150bcecc59700bc32168642880ed46ea960fc601ce97f

Returns the full block header including difficulty, prime chain origin, prime chain type, transaction IDs, and all other fields shown on this page.

How to run these commands: To verify this data independently, open a terminal on your own Primecoin node and run primecoin-cli <command>. Alternatively, open the Primecoin-Qt wallet, go to Help → Debug Window → Console, and type the command directly. The node must be fully synced to this block height for the commands to return results.

Cross-reference on Chainz Explorer

Chainz is an independent Primecoin block explorer. Compare this block's data to verify accuracy.

View Block #2,849,576 on Chainz ↗
Circulating Supply:58,005,926 XPM·at block #6,845,186 · updates every 60s
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