Block #440,452

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 3/12/2014, 10:38:51 AM · Difficulty 10.3528 · 6,356,359 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
54e69bcf20f9d82a834fd08f177c765d469ebf0b44b130a02560a3958806a808

Height

#440,452

Difficulty

10.352753

Transactions

5

Size

2.77 KB

Version

2

Bits

0a5a4e02

Nonce

109,926

Timestamp

3/12/2014, 10:38:51 AM

Confirmations

6,356,359

Merkle Root

d3c919e6ae50e15cb0fa72255470ed712f25b46791d20ae5f8a72d2011ff2cd9
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.

9.136 × 10⁹³(94-digit number)
91365340072726638852…93342718928698111599
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
9.136 × 10⁹³(94-digit number)
91365340072726638852…93342718928698111599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.827 × 10⁹⁴(95-digit number)
18273068014545327770…86685437857396223199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
3.654 × 10⁹⁴(95-digit number)
36546136029090655540…73370875714792446399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
7.309 × 10⁹⁴(95-digit number)
73092272058181311081…46741751429584892799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.461 × 10⁹⁵(96-digit number)
14618454411636262216…93483502859169785599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
2.923 × 10⁹⁵(96-digit number)
29236908823272524432…86967005718339571199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
5.847 × 10⁹⁵(96-digit number)
58473817646545048865…73934011436679142399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.169 × 10⁹⁶(97-digit number)
11694763529309009773…47868022873358284799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
2.338 × 10⁹⁶(97-digit number)
23389527058618019546…95736045746716569599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
4.677 × 10⁹⁶(97-digit number)
46779054117236039092…91472091493433139199
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:57,618,503 XPM·at block #6,796,810 · updates every 60s
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