Block #276,452

TWNLength 9★☆☆☆☆

Bi-Twin Chain · Discovered 11/27/2013, 4:45:36 AM · Difficulty 9.9632 · 6,516,078 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
42145757e9d2226a7755c9b9c4ca4e48513cc9cb922ce169ae362a4d4a2b029e

Height

#276,452

Difficulty

9.963200

Transactions

6

Size

5.89 KB

Version

2

Bits

09f69447

Nonce

119,971

Timestamp

11/27/2013, 4:45:36 AM

Confirmations

6,516,078

Merkle Root

8cd6ffb8fc19a86aa7cf3b65c5b8e1bd742f041eed19a2a8ed4fe2c879d3404a
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.

1.126 × 10⁹³(94-digit number)
11268695688533095502…38448106031637613919
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
1.126 × 10⁹³(94-digit number)
11268695688533095502…38448106031637613919
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
1.126 × 10⁹³(94-digit number)
11268695688533095502…38448106031637613921
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
2.253 × 10⁹³(94-digit number)
22537391377066191005…76896212063275227839
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
2.253 × 10⁹³(94-digit number)
22537391377066191005…76896212063275227841
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
4.507 × 10⁹³(94-digit number)
45074782754132382011…53792424126550455679
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
4.507 × 10⁹³(94-digit number)
45074782754132382011…53792424126550455681
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
9.014 × 10⁹³(94-digit number)
90149565508264764023…07584848253100911359
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
9.014 × 10⁹³(94-digit number)
90149565508264764023…07584848253100911361
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
1.802 × 10⁹⁴(95-digit number)
18029913101652952804…15169696506201822719
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:57,584,208 XPM·at block #6,792,529 · updates every 60s
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