Block #325,842

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 12/23/2013, 8:59:09 AM · Difficulty 10.1946 · 6,482,407 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
3a5a9d25f6be4abc033455d6163ef0bfa7896337ffac88ed96db496ae7f0b936

Height

#325,842

Difficulty

10.194611

Transactions

14

Size

3.61 KB

Version

2

Bits

0a31d205

Nonce

5,979

Timestamp

12/23/2013, 8:59:09 AM

Confirmations

6,482,407

Merkle Root

a24f755868e3e308e87bfbe53b8e317c386fa0d8b09f12876e4affc63daa3b27
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.

2.497 × 10¹⁰²(103-digit number)
24970413044377475555…57507975321814015999
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
2.497 × 10¹⁰²(103-digit number)
24970413044377475555…57507975321814015999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
4.994 × 10¹⁰²(103-digit number)
49940826088754951111…15015950643628031999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
9.988 × 10¹⁰²(103-digit number)
99881652177509902222…30031901287256063999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.997 × 10¹⁰³(104-digit number)
19976330435501980444…60063802574512127999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
3.995 × 10¹⁰³(104-digit number)
39952660871003960889…20127605149024255999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
7.990 × 10¹⁰³(104-digit number)
79905321742007921778…40255210298048511999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.598 × 10¹⁰⁴(105-digit number)
15981064348401584355…80510420596097023999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
3.196 × 10¹⁰⁴(105-digit number)
31962128696803168711…61020841192194047999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
6.392 × 10¹⁰⁴(105-digit number)
63924257393606337422…22041682384388095999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.278 × 10¹⁰⁵(106-digit number)
12784851478721267484…44083364768776191999
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:57,710,037 XPM·at block #6,808,248 · updates every 60s
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