Block #365,317

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 1/18/2014, 4:08:21 PM · Difficulty 10.4244 · 6,439,851 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
5d856fb618d08f9b8a754f20bb8513d11b6760ea091a8b820bbbb2f1e2477b1c

Height

#365,317

Difficulty

10.424426

Transactions

1

Size

698 B

Version

2

Bits

0a6ca72f

Nonce

12,368

Timestamp

1/18/2014, 4:08:21 PM

Confirmations

6,439,851

Merkle Root

e6a775bc943155b83417017e8f3491b158fc4b907cf6641b6a96975848733968
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.

6.077 × 10⁹⁶(97-digit number)
60770229561083769436…75556629544335380799
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
6.077 × 10⁹⁶(97-digit number)
60770229561083769436…75556629544335380799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.215 × 10⁹⁷(98-digit number)
12154045912216753887…51113259088670761599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
2.430 × 10⁹⁷(98-digit number)
24308091824433507774…02226518177341523199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
4.861 × 10⁹⁷(98-digit number)
48616183648867015549…04453036354683046399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
9.723 × 10⁹⁷(98-digit number)
97232367297734031098…08906072709366092799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.944 × 10⁹⁸(99-digit number)
19446473459546806219…17812145418732185599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
3.889 × 10⁹⁸(99-digit number)
38892946919093612439…35624290837464371199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
7.778 × 10⁹⁸(99-digit number)
77785893838187224878…71248581674928742399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.555 × 10⁹⁹(100-digit number)
15557178767637444975…42497163349857484799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
3.111 × 10⁹⁹(100-digit number)
31114357535274889951…84994326699714969599
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:57,685,412 XPM·at block #6,805,167 · updates every 60s
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