Block #321,282

TWNLength 10★★☆☆☆

Bi-Twin Chain · Discovered 12/20/2013, 5:21:57 AM · Difficulty 10.1897 · 6,474,512 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
ad5385f55f0f685788765509063f4166f8502de9dd6a3c38a13e99546ad24f4b

Height

#321,282

Difficulty

10.189660

Transactions

23

Size

10.25 KB

Version

2

Bits

0a308d8e

Nonce

42,284

Timestamp

12/20/2013, 5:21:57 AM

Confirmations

6,474,512

Merkle Root

76f8ce87d45165a2715363c6790f5ef7c1c818317f87d6082f42b2ded9318a3c
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.

3.253 × 10⁹⁵(96-digit number)
32534378637114666182…29199411102979397279
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
3.253 × 10⁹⁵(96-digit number)
32534378637114666182…29199411102979397279
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
3.253 × 10⁹⁵(96-digit number)
32534378637114666182…29199411102979397281
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
6.506 × 10⁹⁵(96-digit number)
65068757274229332365…58398822205958794559
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
6.506 × 10⁹⁵(96-digit number)
65068757274229332365…58398822205958794561
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
1.301 × 10⁹⁶(97-digit number)
13013751454845866473…16797644411917589119
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
1.301 × 10⁹⁶(97-digit number)
13013751454845866473…16797644411917589121
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
2.602 × 10⁹⁶(97-digit number)
26027502909691732946…33595288823835178239
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
2.602 × 10⁹⁶(97-digit number)
26027502909691732946…33595288823835178241
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
5.205 × 10⁹⁶(97-digit number)
52055005819383465892…67190577647670356479
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
5.205 × 10⁹⁶(97-digit number)
52055005819383465892…67190577647670356481
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:57,610,431 XPM·at block #6,795,793 · updates every 60s
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