Block #326,756

TWNLength 10★★☆☆☆

Bi-Twin Chain · Discovered 12/24/2013, 1:01:54 AM · Difficulty 10.1869 · 6,470,082 confirmations

TWN
Bi-Twin Chain

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

Block Header
Block Hash
72dbd330f8fb2c771b6f03003e298135ba8d031b9a00bd51cbfc62fe0f3cd8cc

Height

#326,756

Difficulty

10.186920

Transactions

12

Size

2.64 KB

Version

2

Bits

0a2fda02

Nonce

347,348

Timestamp

12/24/2013, 1:01:54 AM

Confirmations

6,470,082

Merkle Root

27f7f0736ccb5bcf41506a39224c74029ed4ba09163e52229bc883004047f403
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.

2.489 × 10⁹⁹(100-digit number)
24891640778054107320…45584752928655524799
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
2.489 × 10⁹⁹(100-digit number)
24891640778054107320…45584752928655524799
Verify on FactorDB ↗Wolfram Alpha ↗
origin + 1
2.489 × 10⁹⁹(100-digit number)
24891640778054107320…45584752928655524801
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
4.978 × 10⁹⁹(100-digit number)
49783281556108214640…91169505857311049599
Verify on FactorDB ↗Wolfram Alpha ↗
2^1 × origin + 1
4.978 × 10⁹⁹(100-digit number)
49783281556108214640…91169505857311049601
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
9.956 × 10⁹⁹(100-digit number)
99566563112216429280…82339011714622099199
Verify on FactorDB ↗Wolfram Alpha ↗
2^2 × origin + 1
9.956 × 10⁹⁹(100-digit number)
99566563112216429280…82339011714622099201
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
1.991 × 10¹⁰⁰(101-digit number)
19913312622443285856…64678023429244198399
Verify on FactorDB ↗Wolfram Alpha ↗
2^3 × origin + 1
1.991 × 10¹⁰⁰(101-digit number)
19913312622443285856…64678023429244198401
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
3.982 × 10¹⁰⁰(101-digit number)
39826625244886571712…29356046858488396799
Verify on FactorDB ↗Wolfram Alpha ↗
2^4 × origin + 1
3.982 × 10¹⁰⁰(101-digit number)
39826625244886571712…29356046858488396801
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:57,618,716 XPM·at block #6,796,837 · updates every 60s
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