Block #922,485

TWNLength 10★★☆☆☆

Bi-Twin Chain · Discovered 2/4/2015, 12:39:57 PM · Difficulty 10.9152 · 5,868,509 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
d60a310e3e08bdefc34280a9ea5df2e22bbccfedb8399a883acd2ef4a77fac1e

Height

#922,485

Difficulty

10.915197

Transactions

14

Size

121.08 KB

Version

2

Bits

0aea4a61

Nonce

148,434,725

Timestamp

2/4/2015, 12:39:57 PM

Confirmations

5,868,509

Merkle Root

b4324e6096023dc0c56a103f35bf6a1be15c32dea3d0b5b26c260400d1d4e4a4
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.

1.285 × 10⁹⁸(99-digit number)
12858374971630484761…56408277106062929919
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
1.285 × 10⁹⁸(99-digit number)
12858374971630484761…56408277106062929919
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
1.285 × 10⁹⁸(99-digit number)
12858374971630484761…56408277106062929921
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
2.571 × 10⁹⁸(99-digit number)
25716749943260969523…12816554212125859839
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
2.571 × 10⁹⁸(99-digit number)
25716749943260969523…12816554212125859841
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
5.143 × 10⁹⁸(99-digit number)
51433499886521939047…25633108424251719679
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
5.143 × 10⁹⁸(99-digit number)
51433499886521939047…25633108424251719681
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
1.028 × 10⁹⁹(100-digit number)
10286699977304387809…51266216848503439359
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
1.028 × 10⁹⁹(100-digit number)
10286699977304387809…51266216848503439361
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
2.057 × 10⁹⁹(100-digit number)
20573399954608775619…02532433697006878719
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
2.057 × 10⁹⁹(100-digit number)
20573399954608775619…02532433697006878721
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:57,571,966 XPM·at block #6,790,993 · updates every 60s