Block #159,579

1CCLength 9★☆☆☆☆

Cunningham Chain of the First Kind · Discovered 9/11/2013, 5:45:36 AM · Difficulty 9.8648 · 6,644,616 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
86813bbeb23b0de85a7fdd18cd844d96ba5d03f308a9792e43fd24badb6c72ac

Height

#159,579

Difficulty

9.864839

Transactions

2

Size

718 B

Version

2

Bits

09dd6611

Nonce

142,212

Timestamp

9/11/2013, 5:45:36 AM

Confirmations

6,644,616

Merkle Root

308c6bc9f5b3e0fdf6ca85c82e84568b7b8e592b08065795809c94e84e587f91
Transactions (2)
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.

3.784 × 10⁹¹(92-digit number)
37842835446618002531…59966332876181729879
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
3.784 × 10⁹¹(92-digit number)
37842835446618002531…59966332876181729879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
7.568 × 10⁹¹(92-digit number)
75685670893236005063…19932665752363459759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.513 × 10⁹²(93-digit number)
15137134178647201012…39865331504726919519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
3.027 × 10⁹²(93-digit number)
30274268357294402025…79730663009453839039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
6.054 × 10⁹²(93-digit number)
60548536714588804051…59461326018907678079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.210 × 10⁹³(94-digit number)
12109707342917760810…18922652037815356159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
2.421 × 10⁹³(94-digit number)
24219414685835521620…37845304075630712319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
4.843 × 10⁹³(94-digit number)
48438829371671043240…75690608151261424639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
9.687 × 10⁹³(94-digit number)
96877658743342086481…51381216302522849279
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:57,677,614 XPM·at block #6,804,194 · updates every 60s
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