Block #356,824

TWNLength 10★★☆☆☆

Bi-Twin Chain · Discovered 1/13/2014, 12:08:15 AM · Difficulty 10.3825 · 6,445,766 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
27043f9216fdc8cda7b43341ef52de15355a4c3df47d88f6b7a56ca08d8c2f0a

Height

#356,824

Difficulty

10.382532

Transactions

5

Size

2.51 KB

Version

2

Bits

0a61ed9a

Nonce

639,193

Timestamp

1/13/2014, 12:08:15 AM

Confirmations

6,445,766

Merkle Root

845ccfc6e774a8e085c493d2977c1fb65ecf4afe2d61633c564684aa4cd3528b
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.

3.775 × 10¹⁰⁰(101-digit number)
37752067617425956509…64658781373508377599
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
3.775 × 10¹⁰⁰(101-digit number)
37752067617425956509…64658781373508377599
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
3.775 × 10¹⁰⁰(101-digit number)
37752067617425956509…64658781373508377601
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
7.550 × 10¹⁰⁰(101-digit number)
75504135234851913019…29317562747016755199
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
7.550 × 10¹⁰⁰(101-digit number)
75504135234851913019…29317562747016755201
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
1.510 × 10¹⁰¹(102-digit number)
15100827046970382603…58635125494033510399
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
1.510 × 10¹⁰¹(102-digit number)
15100827046970382603…58635125494033510401
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
3.020 × 10¹⁰¹(102-digit number)
30201654093940765207…17270250988067020799
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
3.020 × 10¹⁰¹(102-digit number)
30201654093940765207…17270250988067020801
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
6.040 × 10¹⁰¹(102-digit number)
60403308187881530415…34540501976134041599
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
6.040 × 10¹⁰¹(102-digit number)
60403308187881530415…34540501976134041601
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:57,664,738 XPM·at block #6,802,589 · updates every 60s
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