Block #32,870

1CCLength 8★☆☆☆☆

Cunningham Chain of the First Kind · Discovered 7/14/2013, 3:43:39 AM · Difficulty 7.9911 · 6,762,177 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
79c47b408bc53de8d90a8543cb104197a493eae15026b649f0415fc71bd2bd3a

Height

#32,870

Difficulty

7.991079

Transactions

1

Size

202 B

Version

2

Bits

07fdb753

Nonce

625

Timestamp

7/14/2013, 3:43:39 AM

Confirmations

6,762,177

Merkle Root

0967e51b2db6edd2646140af6aac86671d0b3b7ece10ffc7e031a361f6f05e8e
Transactions (1)
1 in → 1 out15.6400 XPM109 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.

1.954 × 10¹⁰¹(102-digit number)
19547973557522964402…51738992594670145239
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
1.954 × 10¹⁰¹(102-digit number)
19547973557522964402…51738992594670145239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
3.909 × 10¹⁰¹(102-digit number)
39095947115045928804…03477985189340290479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
7.819 × 10¹⁰¹(102-digit number)
78191894230091857609…06955970378680580959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.563 × 10¹⁰²(103-digit number)
15638378846018371521…13911940757361161919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
3.127 × 10¹⁰²(103-digit number)
31276757692036743043…27823881514722323839
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
6.255 × 10¹⁰²(103-digit number)
62553515384073486087…55647763029444647679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.251 × 10¹⁰³(104-digit number)
12510703076814697217…11295526058889295359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
2.502 × 10¹⁰³(104-digit number)
25021406153629394434…22591052117778590719
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 8 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 8

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:57,604,416 XPM·at block #6,795,046 · updates every 60s
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