Block #922,376

TWNLength 10★★☆☆☆

Bi-Twin Chain · Discovered 2/4/2015, 10:30:00 AM · Difficulty 10.9155 · 5,881,363 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
ed647d96867a7215545accc68180ef9f798d790f0d669049da90135a36674d8a

Height

#922,376

Difficulty

10.915531

Transactions

5

Size

115.99 KB

Version

2

Bits

0aea603f

Nonce

1,437,484,216

Timestamp

2/4/2015, 10:30:00 AM

Confirmations

5,881,363

Merkle Root

b672d7f4906f1c5ad18e0471d4e3d0ed988cbcf7fcb9fac51718d412ec941adc
Transactions (5)
1 in → 1 out9.5800 XPM116 B
200 in → 1 out1005.4469 XPM28.93 KB
200 in → 1 out909.8454 XPM28.95 KB
200 in → 1 out997.2822 XPM28.95 KB
200 in → 1 out984.5013 XPM28.95 KB
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.

1.344 × 10⁹⁸(99-digit number)
13445428108898514719…57238893104321925119
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
1.344 × 10⁹⁸(99-digit number)
13445428108898514719…57238893104321925119
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
1.344 × 10⁹⁸(99-digit number)
13445428108898514719…57238893104321925121
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
2.689 × 10⁹⁸(99-digit number)
26890856217797029439…14477786208643850239
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
2.689 × 10⁹⁸(99-digit number)
26890856217797029439…14477786208643850241
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
5.378 × 10⁹⁸(99-digit number)
53781712435594058879…28955572417287700479
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
5.378 × 10⁹⁸(99-digit number)
53781712435594058879…28955572417287700481
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
1.075 × 10⁹⁹(100-digit number)
10756342487118811775…57911144834575400959
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
1.075 × 10⁹⁹(100-digit number)
10756342487118811775…57911144834575400961
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
2.151 × 10⁹⁹(100-digit number)
21512684974237623551…15822289669150801919
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
2.151 × 10⁹⁹(100-digit number)
21512684974237623551…15822289669150801921
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:57,673,949 XPM·at block #6,803,738 · updates every 60s
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