Block #328,976

TWNLength 10★★☆☆☆

Bi-Twin Chain · Discovered 12/25/2013, 3:49:46 PM · Difficulty 10.1697 · 6,474,302 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
1049d8a977d7144ea65438eff84db3f8deafac76903bdcd82527f227d2dced22

Height

#328,976

Difficulty

10.169715

Transactions

5

Size

1.37 KB

Version

2

Bits

0a2b7279

Nonce

158,957

Timestamp

12/25/2013, 3:49:46 PM

Confirmations

6,474,302

Merkle Root

7cb42b631515f9839ec916ce39a97dd8739c15f7b0407e112fd63ab58cd8c3c3
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.

1.168 × 10¹⁰¹(102-digit number)
11687718714171582677…01852751580579901439
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
1.168 × 10¹⁰¹(102-digit number)
11687718714171582677…01852751580579901439
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
1.168 × 10¹⁰¹(102-digit number)
11687718714171582677…01852751580579901441
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
2.337 × 10¹⁰¹(102-digit number)
23375437428343165355…03705503161159802879
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
2.337 × 10¹⁰¹(102-digit number)
23375437428343165355…03705503161159802881
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
4.675 × 10¹⁰¹(102-digit number)
46750874856686330711…07411006322319605759
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
4.675 × 10¹⁰¹(102-digit number)
46750874856686330711…07411006322319605761
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
9.350 × 10¹⁰¹(102-digit number)
93501749713372661422…14822012644639211519
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
9.350 × 10¹⁰¹(102-digit number)
93501749713372661422…14822012644639211521
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
1.870 × 10¹⁰²(103-digit number)
18700349942674532284…29644025289278423039
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
1.870 × 10¹⁰²(103-digit number)
18700349942674532284…29644025289278423041
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:57,670,250 XPM·at block #6,803,277 · updates every 60s
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