Block #292,299

TWNLength 10★★☆☆☆

Bi-Twin Chain · Discovered 12/3/2013, 3:57:31 PM · Difficulty 9.9902 · 6,500,933 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
7fc7a00643c840d27529da14e4859a0a450fad8bd048b5647305e810cd468712

Height

#292,299

Difficulty

9.990239

Transactions

8

Size

3.87 KB

Version

2

Bits

09fd8051

Nonce

22,293

Timestamp

12/3/2013, 3:57:31 PM

Confirmations

6,500,933

Merkle Root

a83ce7f3cfe5008fadd7191cbebe2d3a0289ccbf3fc91446459378bfcdc8fb5c
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.

2.543 × 10⁹²(93-digit number)
25437612040944554793…63938431759666986879
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
2.543 × 10⁹²(93-digit number)
25437612040944554793…63938431759666986879
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
2.543 × 10⁹²(93-digit number)
25437612040944554793…63938431759666986881
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
5.087 × 10⁹²(93-digit number)
50875224081889109587…27876863519333973759
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
5.087 × 10⁹²(93-digit number)
50875224081889109587…27876863519333973761
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
1.017 × 10⁹³(94-digit number)
10175044816377821917…55753727038667947519
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
1.017 × 10⁹³(94-digit number)
10175044816377821917…55753727038667947521
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
2.035 × 10⁹³(94-digit number)
20350089632755643834…11507454077335895039
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
2.035 × 10⁹³(94-digit number)
20350089632755643834…11507454077335895041
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
4.070 × 10⁹³(94-digit number)
40700179265511287669…23014908154671790079
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
4.070 × 10⁹³(94-digit number)
40700179265511287669…23014908154671790081
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:57,589,857 XPM·at block #6,793,231 · updates every 60s
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