Block #468,847

TWNLength 10★★☆☆☆

Bi-Twin Chain · Discovered 3/31/2014, 7:08:35 PM · Difficulty 10.4323 · 6,327,102 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
d981d5c83fb47c6cc5ef53dbd48bf2d847990b7826a1f4373c6ebf40115fc4da

Height

#468,847

Difficulty

10.432276

Transactions

3

Size

706 B

Version

2

Bits

0a6ea9aa

Nonce

52,724

Timestamp

3/31/2014, 7:08:35 PM

Confirmations

6,327,102

Merkle Root

0d1327b0e61693e72fbe3c19aa0b56a78950e3e87767b84c5a21771c87a926de
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.

2.080 × 10⁹²(93-digit number)
20809119360045111899…16844702575329745919
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
2.080 × 10⁹²(93-digit number)
20809119360045111899…16844702575329745919
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
2.080 × 10⁹²(93-digit number)
20809119360045111899…16844702575329745921
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
4.161 × 10⁹²(93-digit number)
41618238720090223798…33689405150659491839
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
4.161 × 10⁹²(93-digit number)
41618238720090223798…33689405150659491841
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
8.323 × 10⁹²(93-digit number)
83236477440180447596…67378810301318983679
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
8.323 × 10⁹²(93-digit number)
83236477440180447596…67378810301318983681
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
1.664 × 10⁹³(94-digit number)
16647295488036089519…34757620602637967359
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
1.664 × 10⁹³(94-digit number)
16647295488036089519…34757620602637967361
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
3.329 × 10⁹³(94-digit number)
33294590976072179038…69515241205275934719
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
3.329 × 10⁹³(94-digit number)
33294590976072179038…69515241205275934721
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:57,611,681 XPM·at block #6,795,948 · updates every 60s
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