Block #231,000

TWNLength 10★★☆☆☆

Bi-Twin Chain · Discovered 10/28/2013, 4:19:31 AM · Difficulty 9.9401 · 6,560,155 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
304509dd99787a50a1d128804b93a751bb1edf307b79ef2c6679d7381d48c4d3

Height

#231,000

Difficulty

9.940090

Transactions

6

Size

3.83 KB

Version

2

Bits

09f0a9bd

Nonce

12,713

Timestamp

10/28/2013, 4:19:31 AM

Confirmations

6,560,155

Merkle Root

969cc6c276e4d226e15d10b62f033e0146dba8de7d5c9be34a16d087c3ef5acd
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.

3.913 × 10⁹²(93-digit number)
39132529857189503209…62725679523641630679
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
3.913 × 10⁹²(93-digit number)
39132529857189503209…62725679523641630679
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
3.913 × 10⁹²(93-digit number)
39132529857189503209…62725679523641630681
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
7.826 × 10⁹²(93-digit number)
78265059714379006418…25451359047283261359
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
7.826 × 10⁹²(93-digit number)
78265059714379006418…25451359047283261361
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
1.565 × 10⁹³(94-digit number)
15653011942875801283…50902718094566522719
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
1.565 × 10⁹³(94-digit number)
15653011942875801283…50902718094566522721
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
3.130 × 10⁹³(94-digit number)
31306023885751602567…01805436189133045439
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
3.130 × 10⁹³(94-digit number)
31306023885751602567…01805436189133045441
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
6.261 × 10⁹³(94-digit number)
62612047771503205134…03610872378266090879
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
6.261 × 10⁹³(94-digit number)
62612047771503205134…03610872378266090881
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:57,573,179 XPM·at block #6,791,154 · updates every 60s
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