Block #317,395

TWNLength 10★★☆☆☆

Bi-Twin Chain · Discovered 12/17/2013, 4:16:19 PM · Difficulty 10.1517 · 6,477,256 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
0051dddf4e62a3697002da734237484e21b517a4c1d79dcc7c89506f66250cf1

Height

#317,395

Difficulty

10.151669

Transactions

2

Size

1.85 KB

Version

2

Bits

0a26d3ca

Nonce

74,587

Timestamp

12/17/2013, 4:16:19 PM

Confirmations

6,477,256

Merkle Root

74359408a6861085f950e7477f1e8913f689ead4ab129e38f3b5a78024cf923a
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.

3.375 × 10⁹⁸(99-digit number)
33751025950869918775…16715397663917944159
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
3.375 × 10⁹⁸(99-digit number)
33751025950869918775…16715397663917944159
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
3.375 × 10⁹⁸(99-digit number)
33751025950869918775…16715397663917944161
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
6.750 × 10⁹⁸(99-digit number)
67502051901739837551…33430795327835888319
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
6.750 × 10⁹⁸(99-digit number)
67502051901739837551…33430795327835888321
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
1.350 × 10⁹⁹(100-digit number)
13500410380347967510…66861590655671776639
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
1.350 × 10⁹⁹(100-digit number)
13500410380347967510…66861590655671776641
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
2.700 × 10⁹⁹(100-digit number)
27000820760695935020…33723181311343553279
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
2.700 × 10⁹⁹(100-digit number)
27000820760695935020…33723181311343553281
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
5.400 × 10⁹⁹(100-digit number)
54001641521391870041…67446362622687106559
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
5.400 × 10⁹⁹(100-digit number)
54001641521391870041…67446362622687106561
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:57,601,257 XPM·at block #6,794,650 · updates every 60s
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