Block #514,561

TWNLength 10★★☆☆☆

Bi-Twin Chain · Discovered 4/28/2014, 5:47:43 AM · Difficulty 10.8388 · 6,280,290 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
0550e07240b6db9e0a00683dff745f880e2ce75723ad6d74ba50d95f05eb068f

Height

#514,561

Difficulty

10.838795

Transactions

9

Size

3.13 KB

Version

2

Bits

0ad6bb46

Nonce

26,217,939

Timestamp

4/28/2014, 5:47:43 AM

Confirmations

6,280,290

Merkle Root

774ac2c0475c0a64c7a06a93f72f97b386d1286f09dd0d1ea624ee6927591214
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.

1.932 × 10⁹⁸(99-digit number)
19325551375991532387…71173018955426065399
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
1.932 × 10⁹⁸(99-digit number)
19325551375991532387…71173018955426065399
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
1.932 × 10⁹⁸(99-digit number)
19325551375991532387…71173018955426065401
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
3.865 × 10⁹⁸(99-digit number)
38651102751983064775…42346037910852130799
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
3.865 × 10⁹⁸(99-digit number)
38651102751983064775…42346037910852130801
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
7.730 × 10⁹⁸(99-digit number)
77302205503966129551…84692075821704261599
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
7.730 × 10⁹⁸(99-digit number)
77302205503966129551…84692075821704261601
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
1.546 × 10⁹⁹(100-digit number)
15460441100793225910…69384151643408523199
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
1.546 × 10⁹⁹(100-digit number)
15460441100793225910…69384151643408523201
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
3.092 × 10⁹⁹(100-digit number)
30920882201586451820…38768303286817046399
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
3.092 × 10⁹⁹(100-digit number)
30920882201586451820…38768303286817046401
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:57,602,837 XPM·at block #6,794,850 · updates every 60s
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