Block #318,259

TWNLength 11★★★☆☆

Bi-Twin Chain · Discovered 12/18/2013, 5:57:12 AM · Difficulty 10.1594 · 6,478,186 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
42959edf07bf099886ad91a8307d74b394ebb3b62287ccac019cd3b0daa55fb0

Height

#318,259

Difficulty

10.159433

Transactions

4

Size

2.91 KB

Version

2

Bits

0a28d094

Nonce

103,799

Timestamp

12/18/2013, 5:57:12 AM

Confirmations

6,478,186

Merkle Root

1303011a3d54bdac74a4d2246c3b9ef95b50ba505a906a9931b8723f67cdcd69
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.

9.868 × 10¹⁰³(104-digit number)
98680146967740834484…04673403978311557119
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
9.868 × 10¹⁰³(104-digit number)
98680146967740834484…04673403978311557119
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
9.868 × 10¹⁰³(104-digit number)
98680146967740834484…04673403978311557121
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
1.973 × 10¹⁰⁴(105-digit number)
19736029393548166896…09346807956623114239
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
1.973 × 10¹⁰⁴(105-digit number)
19736029393548166896…09346807956623114241
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
3.947 × 10¹⁰⁴(105-digit number)
39472058787096333793…18693615913246228479
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
3.947 × 10¹⁰⁴(105-digit number)
39472058787096333793…18693615913246228481
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
7.894 × 10¹⁰⁴(105-digit number)
78944117574192667587…37387231826492456959
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
7.894 × 10¹⁰⁴(105-digit number)
78944117574192667587…37387231826492456961
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
1.578 × 10¹⁰⁵(106-digit number)
15788823514838533517…74774463652984913919
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
1.578 × 10¹⁰⁵(106-digit number)
15788823514838533517…74774463652984913921
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
3.157 × 10¹⁰⁵(106-digit number)
31577647029677067034…49548927305969827839
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:57,615,553 XPM·at block #6,796,444 · updates every 60s
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