Block #344,325

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 1/5/2014, 5:56:52 AM · Difficulty 10.1935 · 6,460,766 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
f0bc78900939d5f3b4f77eab704bcfdcb85672a75136cd7df7ef4a2cc0b04c87

Height

#344,325

Difficulty

10.193536

Transactions

13

Size

15.24 KB

Version

2

Bits

0a318b96

Nonce

296,904

Timestamp

1/5/2014, 5:56:52 AM

Confirmations

6,460,766

Merkle Root

99dbcc3f8ae6a9eb7e75e0336485a9c4513e0e7430ab6762380df848b0343e7a
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.

1.701 × 10¹⁰⁰(101-digit number)
17013198973270380242…75365955083563417599
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
1.701 × 10¹⁰⁰(101-digit number)
17013198973270380242…75365955083563417599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
3.402 × 10¹⁰⁰(101-digit number)
34026397946540760484…50731910167126835199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
6.805 × 10¹⁰⁰(101-digit number)
68052795893081520969…01463820334253670399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.361 × 10¹⁰¹(102-digit number)
13610559178616304193…02927640668507340799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
2.722 × 10¹⁰¹(102-digit number)
27221118357232608387…05855281337014681599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
5.444 × 10¹⁰¹(102-digit number)
54442236714465216775…11710562674029363199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.088 × 10¹⁰²(103-digit number)
10888447342893043355…23421125348058726399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
2.177 × 10¹⁰²(103-digit number)
21776894685786086710…46842250696117452799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
4.355 × 10¹⁰²(103-digit number)
43553789371572173420…93684501392234905599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
8.710 × 10¹⁰²(103-digit number)
87107578743144346840…87369002784469811199
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:57,684,794 XPM·at block #6,805,090 · updates every 60s
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