Block #444,755

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 3/15/2014, 11:00:15 AM · Difficulty 10.3507 · 6,363,820 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
74a5436f6394273eba63b8d481b6d0c135b0eb9077d100647bb67c84ac654716

Height

#444,755

Difficulty

10.350733

Transactions

6

Size

4.61 KB

Version

2

Bits

0a59c99e

Nonce

155,496

Timestamp

3/15/2014, 11:00:15 AM

Confirmations

6,363,820

Merkle Root

55bc201a580a92373359b893cef4998e0aa19569c999275254827874525abee6
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.

2.561 × 10⁹⁶(97-digit number)
25611235456490861877…99770353473151089919
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
2.561 × 10⁹⁶(97-digit number)
25611235456490861877…99770353473151089919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
5.122 × 10⁹⁶(97-digit number)
51222470912981723755…99540706946302179839
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.024 × 10⁹⁷(98-digit number)
10244494182596344751…99081413892604359679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
2.048 × 10⁹⁷(98-digit number)
20488988365192689502…98162827785208719359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
4.097 × 10⁹⁷(98-digit number)
40977976730385379004…96325655570417438719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
8.195 × 10⁹⁷(98-digit number)
81955953460770758008…92651311140834877439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.639 × 10⁹⁸(99-digit number)
16391190692154151601…85302622281669754879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
3.278 × 10⁹⁸(99-digit number)
32782381384308303203…70605244563339509759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
6.556 × 10⁹⁸(99-digit number)
65564762768616606406…41210489126679019519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.311 × 10⁹⁹(100-digit number)
13112952553723321281…82420978253358039039
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:57,712,656 XPM·at block #6,808,574 · updates every 60s
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