Block #323,896

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 12/21/2013, 11:05:45 PM · Difficulty 10.2080 · 6,474,256 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
3811d418688deec1c5c2a92aaa6e6a3c7031105bcc73156f8c257782ada01bf7

Height

#323,896

Difficulty

10.207974

Transactions

13

Size

3.39 KB

Version

2

Bits

0a353dc3

Nonce

109,869

Timestamp

12/21/2013, 11:05:45 PM

Confirmations

6,474,256

Merkle Root

7eb78b3a460772697a8ec22c4eae8f7858a6c9ec3bd795b7685f0fc129b80a80
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.

1.626 × 10⁹⁷(98-digit number)
16265689231683428796…67116810716767395839
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
1.626 × 10⁹⁷(98-digit number)
16265689231683428796…67116810716767395839
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
3.253 × 10⁹⁷(98-digit number)
32531378463366857593…34233621433534791679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
6.506 × 10⁹⁷(98-digit number)
65062756926733715186…68467242867069583359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.301 × 10⁹⁸(99-digit number)
13012551385346743037…36934485734139166719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
2.602 × 10⁹⁸(99-digit number)
26025102770693486074…73868971468278333439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
5.205 × 10⁹⁸(99-digit number)
52050205541386972149…47737942936556666879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.041 × 10⁹⁹(100-digit number)
10410041108277394429…95475885873113333759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
2.082 × 10⁹⁹(100-digit number)
20820082216554788859…90951771746226667519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
4.164 × 10⁹⁹(100-digit number)
41640164433109577719…81903543492453335039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
8.328 × 10⁹⁹(100-digit number)
83280328866219155438…63807086984906670079
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 10 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
UncommonChain length 10

Roughly 1 in 100 blocks. Solid but expected in a healthy network.

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:57,629,215 XPM·at block #6,798,151 · updates every 60s
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