Block #233,527

TWNLength 9★☆☆☆☆

Bi-Twin Chain · Discovered 10/29/2013, 6:54:27 PM · Difficulty 9.9426 · 6,570,266 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
e1ad3e847c3efd12a671ac318ad843a9b7ad5379bd24dd056689ab9237da3c3d

Height

#233,527

Difficulty

9.942640

Transactions

5

Size

2.67 KB

Version

2

Bits

09f150e1

Nonce

88,604

Timestamp

10/29/2013, 6:54:27 PM

Confirmations

6,570,266

Merkle Root

ffa6a4a66e425110716614fdd42d4e74182fc15cbf80ceeda1c439d0a7a80588
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.

3.178 × 10⁹³(94-digit number)
31784748812295554720…54426981583155836799
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
3.178 × 10⁹³(94-digit number)
31784748812295554720…54426981583155836799
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
3.178 × 10⁹³(94-digit number)
31784748812295554720…54426981583155836801
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
6.356 × 10⁹³(94-digit number)
63569497624591109440…08853963166311673599
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
6.356 × 10⁹³(94-digit number)
63569497624591109440…08853963166311673601
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
1.271 × 10⁹⁴(95-digit number)
12713899524918221888…17707926332623347199
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
1.271 × 10⁹⁴(95-digit number)
12713899524918221888…17707926332623347201
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
2.542 × 10⁹⁴(95-digit number)
25427799049836443776…35415852665246694399
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
2.542 × 10⁹⁴(95-digit number)
25427799049836443776…35415852665246694401
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
5.085 × 10⁹⁴(95-digit number)
50855598099672887552…70831705330493388799
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 9 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
CommonChain length 9

Found in most blocks. The baseline for Primecoin's proof-of-work.

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:57,674,386 XPM·at block #6,803,792 · updates every 60s
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