Block #89,361

1CCLength 9★☆☆☆☆

Cunningham Chain of the First Kind · Discovered 7/30/2013, 7:32:50 AM · Difficulty 9.2601 · 6,718,526 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
cb8d17f0844d93d0d89c4d648e53e144eedbc5e7457ed7c463197da02ba52863

Height

#89,361

Difficulty

9.260066

Transactions

2

Size

429 B

Version

2

Bits

094293af

Nonce

44,757

Timestamp

7/30/2013, 7:32:50 AM

Confirmations

6,718,526

Merkle Root

f6362298660f72343e3321f7387fd7bd53e021648dd9f6c5d0933f01060b0761
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.

6.417 × 10¹⁰¹(102-digit number)
64177180389866701110…23404124140513531019
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
6.417 × 10¹⁰¹(102-digit number)
64177180389866701110…23404124140513531019
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.283 × 10¹⁰²(103-digit number)
12835436077973340222…46808248281027062039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
2.567 × 10¹⁰²(103-digit number)
25670872155946680444…93616496562054124079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
5.134 × 10¹⁰²(103-digit number)
51341744311893360888…87232993124108248159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.026 × 10¹⁰³(104-digit number)
10268348862378672177…74465986248216496319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
2.053 × 10¹⁰³(104-digit number)
20536697724757344355…48931972496432992639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
4.107 × 10¹⁰³(104-digit number)
41073395449514688710…97863944992865985279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
8.214 × 10¹⁰³(104-digit number)
82146790899029377421…95727889985731970559
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.642 × 10¹⁰⁴(105-digit number)
16429358179805875484…91455779971463941119
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:57,707,131 XPM·at block #6,807,886 · updates every 60s
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