Block #232,101

1CCLength 9★☆☆☆☆

Cunningham Chain of the First Kind · Discovered 10/28/2013, 9:29:46 PM · Difficulty 9.9409 · 6,557,997 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
576987c88132982ebc8de77cd24e993ed357d9feb20f27edaeff493a091b0aa9

Height

#232,101

Difficulty

9.940935

Transactions

2

Size

426 B

Version

2

Bits

09f0e124

Nonce

10,865

Timestamp

10/28/2013, 9:29:46 PM

Confirmations

6,557,997

Merkle Root

ed93fc149265d35ad5a9fc71662b4f7d0b70d3725edbfce00038073bb2034a6c
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.

6.460 × 10⁹⁵(96-digit number)
64605970815930060382…28562321628449251199
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
6.460 × 10⁹⁵(96-digit number)
64605970815930060382…28562321628449251199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.292 × 10⁹⁶(97-digit number)
12921194163186012076…57124643256898502399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
2.584 × 10⁹⁶(97-digit number)
25842388326372024152…14249286513797004799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
5.168 × 10⁹⁶(97-digit number)
51684776652744048305…28498573027594009599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.033 × 10⁹⁷(98-digit number)
10336955330548809661…56997146055188019199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
2.067 × 10⁹⁷(98-digit number)
20673910661097619322…13994292110376038399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
4.134 × 10⁹⁷(98-digit number)
41347821322195238644…27988584220752076799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
8.269 × 10⁹⁷(98-digit number)
82695642644390477289…55977168441504153599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.653 × 10⁹⁸(99-digit number)
16539128528878095457…11954336883008307199
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:57,564,758 XPM·at block #6,790,097 · updates every 60s