Block #489,987

TWNLength 10★★☆☆☆

Bi-Twin Chain · Discovered 4/13/2014, 2:44:16 PM · Difficulty 10.6719 · 6,305,346 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
e7051cc4deb19be73653abfc7feaac40bfb633773c99e206f893a3e10901ba78

Height

#489,987

Difficulty

10.671886

Transactions

5

Size

1.09 KB

Version

2

Bits

0aac00bc

Nonce

124,015,470

Timestamp

4/13/2014, 2:44:16 PM

Confirmations

6,305,346

Merkle Root

5b22cf5fae1775f25269f22f793b63b4c06449eb004aff56df134d014238adcd
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.

2.938 × 10⁹⁷(98-digit number)
29382552383448656086…75975086987884491339
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
2.938 × 10⁹⁷(98-digit number)
29382552383448656086…75975086987884491339
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
2.938 × 10⁹⁷(98-digit number)
29382552383448656086…75975086987884491341
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
5.876 × 10⁹⁷(98-digit number)
58765104766897312172…51950173975768982679
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
5.876 × 10⁹⁷(98-digit number)
58765104766897312172…51950173975768982681
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
1.175 × 10⁹⁸(99-digit number)
11753020953379462434…03900347951537965359
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
1.175 × 10⁹⁸(99-digit number)
11753020953379462434…03900347951537965361
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
2.350 × 10⁹⁸(99-digit number)
23506041906758924869…07800695903075930719
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
2.350 × 10⁹⁸(99-digit number)
23506041906758924869…07800695903075930721
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
4.701 × 10⁹⁸(99-digit number)
47012083813517849738…15601391806151861439
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
4.701 × 10⁹⁸(99-digit number)
47012083813517849738…15601391806151861441
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:57,606,722 XPM·at block #6,795,332 · updates every 60s
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