Block #922,320

TWNLength 11★★★☆☆

Bi-Twin Chain · Discovered 2/4/2015, 9:31:50 AM · Difficulty 10.9156 · 5,869,576 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
1f2dcbfcbb9532493ba98b7bdadab78673a52eaec73b10ef768caaab463960c4

Height

#922,320

Difficulty

10.915571

Transactions

5

Size

115.96 KB

Version

2

Bits

0aea62e4

Nonce

302,649,506

Timestamp

2/4/2015, 9:31:50 AM

Confirmations

5,869,576

Merkle Root

45a73bbfddb264e99042f514135a49521df1662fa09b8223c20024c2822b1e10
Transactions (5)
1 in → 1 out9.5800 XPM116 B
200 in → 1 out1089.0970 XPM28.94 KB
200 in → 1 out980.1283 XPM28.94 KB
200 in → 1 out957.8146 XPM28.94 KB
200 in → 1 out1056.7765 XPM28.94 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.

2.023 × 10⁹⁵(96-digit number)
20236945889051805958…41998587145328434739
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
2.023 × 10⁹⁵(96-digit number)
20236945889051805958…41998587145328434739
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
2.023 × 10⁹⁵(96-digit number)
20236945889051805958…41998587145328434741
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
4.047 × 10⁹⁵(96-digit number)
40473891778103611916…83997174290656869479
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
4.047 × 10⁹⁵(96-digit number)
40473891778103611916…83997174290656869481
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
8.094 × 10⁹⁵(96-digit number)
80947783556207223833…67994348581313738959
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
8.094 × 10⁹⁵(96-digit number)
80947783556207223833…67994348581313738961
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
1.618 × 10⁹⁶(97-digit number)
16189556711241444766…35988697162627477919
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
1.618 × 10⁹⁶(97-digit number)
16189556711241444766…35988697162627477921
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
3.237 × 10⁹⁶(97-digit number)
32379113422482889533…71977394325254955839
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
3.237 × 10⁹⁶(97-digit number)
32379113422482889533…71977394325254955841
Verify on FactorDB ↗Wolfram Alpha ↗
Difference: 2^4 × origin + 1 − 2^4 × origin − 1 = 2 (twin primes ✓)
Level 5 — Twin Prime Pair (2^5 × origin ± 1)
2^5 × origin − 1
6.475 × 10⁹⁶(97-digit number)
64758226844965779066…43954788650509911679
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 11 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
RareChain length 11

Approximately 1 in 1,000 blocks. Noteworthy discoveries.

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:57,579,117 XPM·at block #6,791,895 · updates every 60s
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