Block #311,850

TWNLength 10★★☆☆☆

Bi-Twin Chain · Discovered 12/14/2013, 6:21:50 PM · Difficulty 9.9956 · 6,487,420 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
71720714dc4843f4e501c4a8fedb2d102438ca76bbed14d926d7542a34960c6f

Height

#311,850

Difficulty

9.995615

Transactions

13

Size

2.84 KB

Version

2

Bits

09fee0a0

Nonce

9,025

Timestamp

12/14/2013, 6:21:50 PM

Confirmations

6,487,420

Merkle Root

04949ff96ce9c9e5222324cf9411ea2ed11133cbf5ff34275770f9efeea45847
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.

2.283 × 10⁹⁵(96-digit number)
22836224882598106309…46619771109566723279
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
2.283 × 10⁹⁵(96-digit number)
22836224882598106309…46619771109566723279
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
2.283 × 10⁹⁵(96-digit number)
22836224882598106309…46619771109566723281
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
4.567 × 10⁹⁵(96-digit number)
45672449765196212618…93239542219133446559
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
4.567 × 10⁹⁵(96-digit number)
45672449765196212618…93239542219133446561
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
9.134 × 10⁹⁵(96-digit number)
91344899530392425236…86479084438266893119
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
9.134 × 10⁹⁵(96-digit number)
91344899530392425236…86479084438266893121
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
1.826 × 10⁹⁶(97-digit number)
18268979906078485047…72958168876533786239
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
1.826 × 10⁹⁶(97-digit number)
18268979906078485047…72958168876533786241
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
3.653 × 10⁹⁶(97-digit number)
36537959812156970094…45916337753067572479
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
3.653 × 10⁹⁶(97-digit number)
36537959812156970094…45916337753067572481
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:57,638,199 XPM·at block #6,799,269 · updates every 60s
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