Block #295,390

TWNLength 10★★☆☆☆

Bi-Twin Chain · Discovered 12/5/2013, 10:13:05 AM · Difficulty 9.9914 · 6,501,452 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
03691a86f6a8245ff25d8b4c00fbe84f06158735093e845187c0ae8820b27063

Height

#295,390

Difficulty

9.991357

Transactions

11

Size

15.64 KB

Version

2

Bits

09fdc993

Nonce

26,641

Timestamp

12/5/2013, 10:13:05 AM

Confirmations

6,501,452

Merkle Root

5820cb7aa286cfea62ca3607fc24ad51f73dd3b934ac0e227f7acf0aa55a7fb0
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.

4.680 × 10⁹⁶(97-digit number)
46802559924494550398…52525411145925489279
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
4.680 × 10⁹⁶(97-digit number)
46802559924494550398…52525411145925489279
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
4.680 × 10⁹⁶(97-digit number)
46802559924494550398…52525411145925489281
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
9.360 × 10⁹⁶(97-digit number)
93605119848989100797…05050822291850978559
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
9.360 × 10⁹⁶(97-digit number)
93605119848989100797…05050822291850978561
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
1.872 × 10⁹⁷(98-digit number)
18721023969797820159…10101644583701957119
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
1.872 × 10⁹⁷(98-digit number)
18721023969797820159…10101644583701957121
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
3.744 × 10⁹⁷(98-digit number)
37442047939595640318…20203289167403914239
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
3.744 × 10⁹⁷(98-digit number)
37442047939595640318…20203289167403914241
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
7.488 × 10⁹⁷(98-digit number)
74884095879191280637…40406578334807828479
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
7.488 × 10⁹⁷(98-digit number)
74884095879191280637…40406578334807828481
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:57,618,748 XPM·at block #6,796,841 · updates every 60s
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