Block #718,544

TWNLength 10★★☆☆☆

Bi-Twin Chain · Discovered 9/13/2014, 8:17:13 AM · Difficulty 10.9493 · 6,087,248 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
639ac5cc933499c5d6d51ceb86588d411fed1e086283bedc3d4675a96f077094

Height

#718,544

Difficulty

10.949337

Transactions

3

Size

27.68 KB

Version

2

Bits

0af307c6

Nonce

180,618,844

Timestamp

9/13/2014, 8:17:13 AM

Confirmations

6,087,248

Merkle Root

58ab712a6fe31b81ae95ea2404b1dd16be0e950fcaf465ac9adbb09135f00215
Transactions (3)
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.

3.324 × 10⁹⁷(98-digit number)
33244320296395474026…30163063185200814079
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
3.324 × 10⁹⁷(98-digit number)
33244320296395474026…30163063185200814079
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
3.324 × 10⁹⁷(98-digit number)
33244320296395474026…30163063185200814081
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
6.648 × 10⁹⁷(98-digit number)
66488640592790948052…60326126370401628159
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
6.648 × 10⁹⁷(98-digit number)
66488640592790948052…60326126370401628161
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
1.329 × 10⁹⁸(99-digit number)
13297728118558189610…20652252740803256319
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
1.329 × 10⁹⁸(99-digit number)
13297728118558189610…20652252740803256321
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
2.659 × 10⁹⁸(99-digit number)
26595456237116379221…41304505481606512639
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
2.659 × 10⁹⁸(99-digit number)
26595456237116379221…41304505481606512641
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
5.319 × 10⁹⁸(99-digit number)
53190912474232758442…82609010963213025279
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
5.319 × 10⁹⁸(99-digit number)
53190912474232758442…82609010963213025281
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:57,690,419 XPM·at block #6,805,791 · updates every 60s
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