Block #264,675

TWNLength 9★☆☆☆☆

Bi-Twin Chain · Discovered 11/18/2013, 9:53:53 PM · Difficulty 9.9639 · 6,527,792 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
f1d25f488676e344ae7642701c33dfee1dcb8daf741827ea30f09ebcd689c1aa

Height

#264,675

Difficulty

9.963949

Transactions

7

Size

2.42 KB

Version

2

Bits

09f6c55c

Nonce

7,656

Timestamp

11/18/2013, 9:53:53 PM

Confirmations

6,527,792

Merkle Root

da81e112701f3461d93deb21a6db79e83b19fcb524a43c3bf662ae57ce8006d8
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.

1.456 × 10⁹⁶(97-digit number)
14568439450350865896…13407726700883815039
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
1.456 × 10⁹⁶(97-digit number)
14568439450350865896…13407726700883815039
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
1.456 × 10⁹⁶(97-digit number)
14568439450350865896…13407726700883815041
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
2.913 × 10⁹⁶(97-digit number)
29136878900701731793…26815453401767630079
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
2.913 × 10⁹⁶(97-digit number)
29136878900701731793…26815453401767630081
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
5.827 × 10⁹⁶(97-digit number)
58273757801403463586…53630906803535260159
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
5.827 × 10⁹⁶(97-digit number)
58273757801403463586…53630906803535260161
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
1.165 × 10⁹⁷(98-digit number)
11654751560280692717…07261813607070520319
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
1.165 × 10⁹⁷(98-digit number)
11654751560280692717…07261813607070520321
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
2.330 × 10⁹⁷(98-digit number)
23309503120561385434…14523627214141040639
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 9 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
CommonChain length 9

Found in most blocks. The baseline for Primecoin's proof-of-work.

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:57,583,698 XPM·at block #6,792,466 · updates every 60s
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