Block #907,454

TWNLength 10★★☆☆☆

Bi-Twin Chain · Discovered 1/24/2015, 3:03:35 AM · Difficulty 10.9351 · 5,888,166 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
a9d4289906a53cc9f2dd334c1cfc97281aac83ecb2acfa6f8d713568a632bebd

Height

#907,454

Difficulty

10.935144

Transactions

10

Size

6.52 KB

Version

2

Bits

0aef6595

Nonce

294,413,076

Timestamp

1/24/2015, 3:03:35 AM

Confirmations

5,888,166

Merkle Root

11c6cabce1ff7695ea4884312cf6f5ca7fa59ba71df7e421992a73f4db0b5eec
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.

8.842 × 10⁹⁷(98-digit number)
88429259689465506935…85361157703825326079
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
8.842 × 10⁹⁷(98-digit number)
88429259689465506935…85361157703825326079
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
8.842 × 10⁹⁷(98-digit number)
88429259689465506935…85361157703825326081
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
1.768 × 10⁹⁸(99-digit number)
17685851937893101387…70722315407650652159
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
1.768 × 10⁹⁸(99-digit number)
17685851937893101387…70722315407650652161
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
3.537 × 10⁹⁸(99-digit number)
35371703875786202774…41444630815301304319
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
3.537 × 10⁹⁸(99-digit number)
35371703875786202774…41444630815301304321
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
7.074 × 10⁹⁸(99-digit number)
70743407751572405548…82889261630602608639
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
7.074 × 10⁹⁸(99-digit number)
70743407751572405548…82889261630602608641
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
1.414 × 10⁹⁹(100-digit number)
14148681550314481109…65778523261205217279
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
1.414 × 10⁹⁹(100-digit number)
14148681550314481109…65778523261205217281
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:57,609,026 XPM·at block #6,795,619 · updates every 60s
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