1. #6,796,286TWN11 primes

    Bi-Twin · ⛏️ coinsforall.io

Block #56,432

1CCLength 9★☆☆☆☆

Cunningham Chain of the First Kind · Discovered 7/17/2013, 8:00:01 AM · Difficulty 8.9486 · 6,739,855 confirmations

1CC
Cunningham Chain of the First Kind

A sequence where each prime is double the previous prime plus one.

Block Header
Block Hash
d32649696d0ebe55b740676f8ebdcf77d2af86aad313e7a82aa6c98d3feca6b5

Height

#56,432

Difficulty

8.948605

Transactions

2

Size

3.41 KB

Version

2

Bits

08f2d7bf

Nonce

1,150

Timestamp

7/17/2013, 8:00:01 AM

Confirmations

6,739,855

Merkle Root

99ad58d5a7dad629572dedb86004730ab2fcb8362608395031fc04097dd7a5e0
Transactions (2)
1 in → 1 out12.5100 XPM110 B
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.

4.007 × 10⁸⁹(90-digit number)
40070788637838359681…72196309456931516449
Discovered Prime Numbers
p_k = 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.

1
origin − 1
4.007 × 10⁸⁹(90-digit number)
40070788637838359681…72196309456931516449
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
8.014 × 10⁸⁹(90-digit number)
80141577275676719363…44392618913863032899
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.602 × 10⁹⁰(91-digit number)
16028315455135343872…88785237827726065799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
3.205 × 10⁹⁰(91-digit number)
32056630910270687745…77570475655452131599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
6.411 × 10⁹⁰(91-digit number)
64113261820541375490…55140951310904263199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.282 × 10⁹¹(92-digit number)
12822652364108275098…10281902621808526399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
2.564 × 10⁹¹(92-digit number)
25645304728216550196…20563805243617052799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
5.129 × 10⁹¹(92-digit number)
51290609456433100392…41127610487234105599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.025 × 10⁹²(93-digit number)
10258121891286620078…82255220974468211199
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 Cunningham Chain of the First Kind. 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 1CC formula:

1CC: p₁ (first prime), p₂ = 2p₁ + 1, p₃ = 2p₂ + 1, …
Circulating Supply:57,614,299 XPM·at block #6,796,286 · updates every 60s
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