Block #641,548

TWNLength 11★★★☆☆

Bi-Twin Chain · Discovered 7/21/2014, 1:35:39 AM · Difficulty 10.9574 · 6,154,714 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
57410e679875acbfcc026fb94e0d14b52cad6c745392c377246a23fe1175eb76

Height

#641,548

Difficulty

10.957369

Transactions

3

Size

3.17 KB

Version

2

Bits

0af51625

Nonce

34,715,807

Timestamp

7/21/2014, 1:35:39 AM

Confirmations

6,154,714

Merkle Root

f1cad61d983ba10782c06a0f678dc44fe5ad2e9fb4ca3a01e19d480083ecc8be
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.

2.489 × 10⁹⁴(95-digit number)
24895368988336116098…28875669164192761459
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
2.489 × 10⁹⁴(95-digit number)
24895368988336116098…28875669164192761459
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
2.489 × 10⁹⁴(95-digit number)
24895368988336116098…28875669164192761461
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
4.979 × 10⁹⁴(95-digit number)
49790737976672232197…57751338328385522919
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
4.979 × 10⁹⁴(95-digit number)
49790737976672232197…57751338328385522921
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
9.958 × 10⁹⁴(95-digit number)
99581475953344464394…15502676656771045839
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
9.958 × 10⁹⁴(95-digit number)
99581475953344464394…15502676656771045841
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
1.991 × 10⁹⁵(96-digit number)
19916295190668892878…31005353313542091679
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
1.991 × 10⁹⁵(96-digit number)
19916295190668892878…31005353313542091681
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
3.983 × 10⁹⁵(96-digit number)
39832590381337785757…62010706627084183359
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
3.983 × 10⁹⁵(96-digit number)
39832590381337785757…62010706627084183361
Verify on FactorDB ↗Wolfram Alpha ↗
Difference: 2^4 × origin + 1 − 2^4 × origin − 1 = 2 (twin primes ✓)
Level 5 — Twin Prime Pair (2^5 × origin ± 1)
2^5 × origin − 1
7.966 × 10⁹⁵(96-digit number)
79665180762675571515…24021413254168366719
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 11 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
RareChain length 11

Approximately 1 in 1,000 blocks. Noteworthy discoveries.

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:57,614,095 XPM·at block #6,796,261 · updates every 60s
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