Home/Chain Registry/Block #854,961

Block #854,961

TWNLength 10★★☆☆☆

Bi-Twin Chain · Discovered 12/16/2014, 12:29:36 AM · Difficulty 10.9684 · 5,938,469 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
cd3c92436dc347af4d750d1225a5132ba6ef3f2eb6aa96e95daf6b5886958268

Height

#854,961

Difficulty

10.968418

Transactions

13

Size

4.51 KB

Version

2

Bits

0af7ea3b

Nonce

607,935,155

Timestamp

12/16/2014, 12:29:36 AM

Confirmations

5,938,469

Merkle Root

a43227086fbeb3dac3a4c779ed7264b4eb429a1fde02b50bdd119ca64e9e5fa6
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.

7.973 × 10⁹³(94-digit number)
79738288594396519200…14001710195976670600
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
7.973 × 10⁹³(94-digit number)
79738288594396519200…14001710195976670599
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
7.973 × 10⁹³(94-digit number)
79738288594396519200…14001710195976670601
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
1.594 × 10⁹⁴(95-digit number)
15947657718879303840…28003420391953341199
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
1.594 × 10⁹⁴(95-digit number)
15947657718879303840…28003420391953341201
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
3.189 × 10⁹⁴(95-digit number)
31895315437758607680…56006840783906682399
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
3.189 × 10⁹⁴(95-digit number)
31895315437758607680…56006840783906682401
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
6.379 × 10⁹⁴(95-digit number)
63790630875517215360…12013681567813364799
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
6.379 × 10⁹⁴(95-digit number)
63790630875517215360…12013681567813364801
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
1.275 × 10⁹⁵(96-digit number)
12758126175103443072…24027363135626729599
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
1.275 × 10⁹⁵(96-digit number)
12758126175103443072…24027363135626729601
Verify on FactorDB ↗Wolfram Alpha ↗
Difference: 2^4 × origin + 1 − 2^4 × origin − 1 = 2 (twin primes ✓)

What this block proved

The miner who found this block proved the existence of 10 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
UncommonChain length 10
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 854961

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 cd3c92436dc347af4d750d1225a5132ba6ef3f2eb6aa96e95daf6b5886958268

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 #854,961 on Chainz ↗
Circulating Supply:57,591,425 XPM·at block #6,793,429 · updates every 60s
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