Block #142,932

TWNLength 9★☆☆☆☆

Bi-Twin Chain · Discovered 8/31/2013, 7:25:46 AM · Difficulty 9.8374 · 6,658,868 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
cb66446715117fb93eb5c3514ccc64a6ca945fdecb1b0a134206552ad571ae68

Height

#142,932

Difficulty

9.837419

Transactions

7

Size

1.81 KB

Version

2

Bits

09d6611e

Nonce

224,284

Timestamp

8/31/2013, 7:25:46 AM

Confirmations

6,658,868

Merkle Root

8b44cc62ea4fbd28a6f4333df6ab97c366a28b4a18226cff10706bba732a6e96
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.

5.747 × 10⁹⁴(95-digit number)
57477168798111019550…35733806534519882719
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
5.747 × 10⁹⁴(95-digit number)
57477168798111019550…35733806534519882719
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
5.747 × 10⁹⁴(95-digit number)
57477168798111019550…35733806534519882721
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
1.149 × 10⁹⁵(96-digit number)
11495433759622203910…71467613069039765439
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
1.149 × 10⁹⁵(96-digit number)
11495433759622203910…71467613069039765441
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
2.299 × 10⁹⁵(96-digit number)
22990867519244407820…42935226138079530879
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
2.299 × 10⁹⁵(96-digit number)
22990867519244407820…42935226138079530881
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
4.598 × 10⁹⁵(96-digit number)
45981735038488815640…85870452276159061759
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
4.598 × 10⁹⁵(96-digit number)
45981735038488815640…85870452276159061761
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
9.196 × 10⁹⁵(96-digit number)
91963470076977631281…71740904552318123519
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:57,658,490 XPM·at block #6,801,799 · updates every 60s
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