Block #295,632

TWNLength 9★☆☆☆☆

Bi-Twin Chain · Discovered 12/5/2013, 1:30:10 PM · Difficulty 9.9914 · 6,507,966 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
b7627ec0e5f89445cd829cc24fd94522358ab92111a37d161d56340abe236191

Height

#295,632

Difficulty

9.991443

Transactions

8

Size

20.18 KB

Version

2

Bits

09fdcf3b

Nonce

231,960

Timestamp

12/5/2013, 1:30:10 PM

Confirmations

6,507,966

Merkle Root

ebd5a5cba6a1fd9bb18c0c0b1a5b1edba8419a6aff80036af02f50ab1454a569
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.

3.792 × 10⁹³(94-digit number)
37921042946490613753…74342518680319978399
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
3.792 × 10⁹³(94-digit number)
37921042946490613753…74342518680319978399
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
3.792 × 10⁹³(94-digit number)
37921042946490613753…74342518680319978401
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
7.584 × 10⁹³(94-digit number)
75842085892981227506…48685037360639956799
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
7.584 × 10⁹³(94-digit number)
75842085892981227506…48685037360639956801
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
1.516 × 10⁹⁴(95-digit number)
15168417178596245501…97370074721279913599
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
1.516 × 10⁹⁴(95-digit number)
15168417178596245501…97370074721279913601
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
3.033 × 10⁹⁴(95-digit number)
30336834357192491002…94740149442559827199
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
3.033 × 10⁹⁴(95-digit number)
30336834357192491002…94740149442559827201
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
6.067 × 10⁹⁴(95-digit number)
60673668714384982005…89480298885119654399
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:57,672,822 XPM·at block #6,803,597 · updates every 60s
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