Block #325,655

TWNLength 10★★☆☆☆

Bi-Twin Chain · Discovered 12/23/2013, 5:38:31 AM · Difficulty 10.1965 · 6,469,890 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
7a75262d669eedccf104b689491a360a04031d658f42b4b1acfeeaae215301be

Height

#325,655

Difficulty

10.196502

Transactions

8

Size

1.89 KB

Version

2

Bits

0a324df8

Nonce

20,175

Timestamp

12/23/2013, 5:38:31 AM

Confirmations

6,469,890

Merkle Root

398b3f5284825e44e85c3d0fbf8cd177afbccb3a0ecb3a41252b3465c95bb92b
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.

7.131 × 10⁹⁶(97-digit number)
71312457183309579848…72693159651515407339
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
7.131 × 10⁹⁶(97-digit number)
71312457183309579848…72693159651515407339
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
7.131 × 10⁹⁶(97-digit number)
71312457183309579848…72693159651515407341
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
1.426 × 10⁹⁷(98-digit number)
14262491436661915969…45386319303030814679
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
1.426 × 10⁹⁷(98-digit number)
14262491436661915969…45386319303030814681
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
2.852 × 10⁹⁷(98-digit number)
28524982873323831939…90772638606061629359
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
2.852 × 10⁹⁷(98-digit number)
28524982873323831939…90772638606061629361
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
5.704 × 10⁹⁷(98-digit number)
57049965746647663878…81545277212123258719
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
5.704 × 10⁹⁷(98-digit number)
57049965746647663878…81545277212123258721
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
1.140 × 10⁹⁸(99-digit number)
11409993149329532775…63090554424246517439
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
1.140 × 10⁹⁸(99-digit number)
11409993149329532775…63090554424246517441
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:57,608,423 XPM·at block #6,795,544 · updates every 60s
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