Home/Chain Registry/Block #279,278

Block #279,278

TWNLength 10★★☆☆☆

Bi-Twin Chain · Discovered 11/28/2013, 7:19:51 AM · Difficulty 9.9713 · 6,516,711 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
8ac22a71d57335f9ea774bc5df8ea34f42c274812ba22e81e15c32bbb6cfd4e8

Height

#279,278

Difficulty

9.971260

Transactions

7

Size

1.59 KB

Version

2

Bits

09f8a47a

Nonce

25,984

Timestamp

11/28/2013, 7:19:51 AM

Confirmations

6,516,711

Merkle Root

4f41a2e87162c2da8737c82707a67747f1c803ba994b29f8e74f930b24ddb4a9
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.

1.153 × 10⁹⁴(95-digit number)
11531416251447277539…51108248468286798650
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
1.153 × 10⁹⁴(95-digit number)
11531416251447277539…51108248468286798649
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
1.153 × 10⁹⁴(95-digit number)
11531416251447277539…51108248468286798651
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
2.306 × 10⁹⁴(95-digit number)
23062832502894555079…02216496936573597299
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
2.306 × 10⁹⁴(95-digit number)
23062832502894555079…02216496936573597301
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
4.612 × 10⁹⁴(95-digit number)
46125665005789110159…04432993873147194599
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
4.612 × 10⁹⁴(95-digit number)
46125665005789110159…04432993873147194601
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
9.225 × 10⁹⁴(95-digit number)
92251330011578220319…08865987746294389199
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
9.225 × 10⁹⁴(95-digit number)
92251330011578220319…08865987746294389201
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
1.845 × 10⁹⁵(96-digit number)
18450266002315644063…17731975492588778399
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
1.845 × 10⁹⁵(96-digit number)
18450266002315644063…17731975492588778401
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 279278

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 8ac22a71d57335f9ea774bc5df8ea34f42c274812ba22e81e15c32bbb6cfd4e8

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 #279,278 on Chainz ↗
Circulating Supply:57,612,007 XPM·at block #6,795,988 · updates every 60s
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