Block #316,763

TWNLength 10★★☆☆☆

Bi-Twin Chain · Discovered 12/17/2013, 6:26:08 AM · Difficulty 10.1447 · 6,488,376 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
e849da07315a4581e07d65d3a5366cb67647fbe6ac787f06e5929fbe811d1401

Height

#316,763

Difficulty

10.144664

Transactions

29

Size

8.81 KB

Version

2

Bits

0a2508af

Nonce

8,635

Timestamp

12/17/2013, 6:26:08 AM

Confirmations

6,488,376

Merkle Root

77918598d44a0229ac60cc172067603bacdb0b805c55bdfe099a75d5abfb2ff1
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.

5.209 × 10⁹⁶(97-digit number)
52095366916807365069…32674138541471095079
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
5.209 × 10⁹⁶(97-digit number)
52095366916807365069…32674138541471095079
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
5.209 × 10⁹⁶(97-digit number)
52095366916807365069…32674138541471095081
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
1.041 × 10⁹⁷(98-digit number)
10419073383361473013…65348277082942190159
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
1.041 × 10⁹⁷(98-digit number)
10419073383361473013…65348277082942190161
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
2.083 × 10⁹⁷(98-digit number)
20838146766722946027…30696554165884380319
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
2.083 × 10⁹⁷(98-digit number)
20838146766722946027…30696554165884380321
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
4.167 × 10⁹⁷(98-digit number)
41676293533445892055…61393108331768760639
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
4.167 × 10⁹⁷(98-digit number)
41676293533445892055…61393108331768760641
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
8.335 × 10⁹⁷(98-digit number)
83352587066891784111…22786216663537521279
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
8.335 × 10⁹⁷(98-digit number)
83352587066891784111…22786216663537521281
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:57,685,177 XPM·at block #6,805,138 · updates every 60s
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