Block #396,020

TWNLength 10★★☆☆☆

Bi-Twin Chain · Discovered 2/9/2014, 3:28:17 AM · Difficulty 10.4092 · 6,405,793 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
d9e305e86217f713f8c9173af5321ca28fcd802b763ca966139826ebdbe9dd81

Height

#396,020

Difficulty

10.409224

Transactions

3

Size

1.08 KB

Version

2

Bits

0a68c2e8

Nonce

1,070

Timestamp

2/9/2014, 3:28:17 AM

Confirmations

6,405,793

Merkle Root

a11422b74a636e37c0d2e7a0ceff9fcd6a95fcd04ff2fc0f1f148db5de7b75f8
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.

3.006 × 10¹⁰²(103-digit number)
30063930314101004219…52047625118723112959
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
3.006 × 10¹⁰²(103-digit number)
30063930314101004219…52047625118723112959
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
3.006 × 10¹⁰²(103-digit number)
30063930314101004219…52047625118723112961
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
6.012 × 10¹⁰²(103-digit number)
60127860628202008438…04095250237446225919
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
6.012 × 10¹⁰²(103-digit number)
60127860628202008438…04095250237446225921
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
1.202 × 10¹⁰³(104-digit number)
12025572125640401687…08190500474892451839
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
1.202 × 10¹⁰³(104-digit number)
12025572125640401687…08190500474892451841
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
2.405 × 10¹⁰³(104-digit number)
24051144251280803375…16381000949784903679
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
2.405 × 10¹⁰³(104-digit number)
24051144251280803375…16381000949784903681
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
4.810 × 10¹⁰³(104-digit number)
48102288502561606751…32762001899569807359
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
4.810 × 10¹⁰³(104-digit number)
48102288502561606751…32762001899569807361
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:57,658,596 XPM·at block #6,801,812 · updates every 60s
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