Block #395,780

TWNLength 10★★☆☆☆

Bi-Twin Chain · Discovered 2/8/2014, 11:29:48 PM · Difficulty 10.4098 · 6,395,707 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
994d2902cf8b903c3fcc6dda2499b766597368230637da036b34bf69b9583f0b

Height

#395,780

Difficulty

10.409821

Transactions

5

Size

1.51 KB

Version

2

Bits

0a68ea07

Nonce

110,114

Timestamp

2/8/2014, 11:29:48 PM

Confirmations

6,395,707

Merkle Root

ca15ba40d3426787cbecb8b04cf6394ecac87ea76b779fdcbccc87b57fa7dd4c
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.

9.533 × 10⁹⁶(97-digit number)
95331186586523836680…55476797117121136359
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
9.533 × 10⁹⁶(97-digit number)
95331186586523836680…55476797117121136359
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
9.533 × 10⁹⁶(97-digit number)
95331186586523836680…55476797117121136361
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
1.906 × 10⁹⁷(98-digit number)
19066237317304767336…10953594234242272719
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
1.906 × 10⁹⁷(98-digit number)
19066237317304767336…10953594234242272721
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
3.813 × 10⁹⁷(98-digit number)
38132474634609534672…21907188468484545439
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
3.813 × 10⁹⁷(98-digit number)
38132474634609534672…21907188468484545441
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
7.626 × 10⁹⁷(98-digit number)
76264949269219069344…43814376936969090879
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
7.626 × 10⁹⁷(98-digit number)
76264949269219069344…43814376936969090881
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
1.525 × 10⁹⁸(99-digit number)
15252989853843813868…87628753873938181759
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
1.525 × 10⁹⁸(99-digit number)
15252989853843813868…87628753873938181761
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:57,575,836 XPM·at block #6,791,486 · updates every 60s
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