Block #337,845

TWNLength 10★★☆☆☆

Bi-Twin Chain · Discovered 12/31/2013, 11:56:53 PM · Difficulty 10.1295 · 6,467,430 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
d2915991b83337288c1eeff338c4f47eacb84989c73902d227b39ca685435dc2

Height

#337,845

Difficulty

10.129476

Transactions

11

Size

3.51 KB

Version

2

Bits

0a21255e

Nonce

56,512

Timestamp

12/31/2013, 11:56:53 PM

Confirmations

6,467,430

Merkle Root

73b73c7669457207e1493729d09b66a2cd327916d07988739a21008d466375ff
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.

1.044 × 10⁹⁸(99-digit number)
10440846815716650327…06003324618258329599
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
1.044 × 10⁹⁸(99-digit number)
10440846815716650327…06003324618258329599
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
1.044 × 10⁹⁸(99-digit number)
10440846815716650327…06003324618258329601
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
2.088 × 10⁹⁸(99-digit number)
20881693631433300654…12006649236516659199
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
2.088 × 10⁹⁸(99-digit number)
20881693631433300654…12006649236516659201
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
4.176 × 10⁹⁸(99-digit number)
41763387262866601309…24013298473033318399
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
4.176 × 10⁹⁸(99-digit number)
41763387262866601309…24013298473033318401
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
8.352 × 10⁹⁸(99-digit number)
83526774525733202618…48026596946066636799
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
8.352 × 10⁹⁸(99-digit number)
83526774525733202618…48026596946066636801
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
1.670 × 10⁹⁹(100-digit number)
16705354905146640523…96053193892133273599
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
1.670 × 10⁹⁹(100-digit number)
16705354905146640523…96053193892133273601
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.

★★☆☆☆
Rarity
UncommonChain length 10

Roughly 1 in 100 blocks. Solid but expected in a healthy network.

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
Circulating Supply:57,686,272 XPM·at block #6,805,274 · updates every 60s
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