Block #231,834

TWNLength 10★★☆☆☆

Bi-Twin Chain · Discovered 10/28/2013, 5:42:32 PM · Difficulty 9.9405 · 6,559,160 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
a42e3e74ebce4b84342a416f38a9e8daad6ce1709b818b9d8cc7efd6be38b2a5

Height

#231,834

Difficulty

9.940463

Transactions

7

Size

2.10 KB

Version

2

Bits

09f0c22a

Nonce

85,640

Timestamp

10/28/2013, 5:42:32 PM

Confirmations

6,559,160

Merkle Root

5749d45294cb5671c9351d6363d106a15991e9a138fbcd27ce1b61cdc91aecdb
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.

3.301 × 10⁹²(93-digit number)
33015487472575554079…96416025464917025519
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
3.301 × 10⁹²(93-digit number)
33015487472575554079…96416025464917025519
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
3.301 × 10⁹²(93-digit number)
33015487472575554079…96416025464917025521
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
6.603 × 10⁹²(93-digit number)
66030974945151108158…92832050929834051039
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
6.603 × 10⁹²(93-digit number)
66030974945151108158…92832050929834051041
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
1.320 × 10⁹³(94-digit number)
13206194989030221631…85664101859668102079
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
1.320 × 10⁹³(94-digit number)
13206194989030221631…85664101859668102081
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
2.641 × 10⁹³(94-digit number)
26412389978060443263…71328203719336204159
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
2.641 × 10⁹³(94-digit number)
26412389978060443263…71328203719336204161
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
5.282 × 10⁹³(94-digit number)
52824779956120886527…42656407438672408319
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
5.282 × 10⁹³(94-digit number)
52824779956120886527…42656407438672408321
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:57,571,966 XPM·at block #6,790,993 · updates every 60s