Block #350,406

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 1/9/2014, 12:47:26 AM · Difficulty 10.2877 · 6,446,041 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
4187c5a29705f790cec67b0cd607e7efd65114e158eefc9feb37621f2110b794

Height

#350,406

Difficulty

10.287686

Transactions

3

Size

1.22 KB

Version

2

Bits

0a49a5cc

Nonce

52,079

Timestamp

1/9/2014, 12:47:26 AM

Confirmations

6,446,041

Merkle Root

73bf63dcce59bd81ebc2ba258fa75139c17084fc97474079b8bc96e490a3d2ef
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.

2.741 × 10⁹⁵(96-digit number)
27419483083922571368…97454666747435445399
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
2.741 × 10⁹⁵(96-digit number)
27419483083922571368…97454666747435445399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
5.483 × 10⁹⁵(96-digit number)
54838966167845142737…94909333494870890799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.096 × 10⁹⁶(97-digit number)
10967793233569028547…89818666989741781599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
2.193 × 10⁹⁶(97-digit number)
21935586467138057094…79637333979483563199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
4.387 × 10⁹⁶(97-digit number)
43871172934276114189…59274667958967126399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
8.774 × 10⁹⁶(97-digit number)
87742345868552228379…18549335917934252799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.754 × 10⁹⁷(98-digit number)
17548469173710445675…37098671835868505599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
3.509 × 10⁹⁷(98-digit number)
35096938347420891351…74197343671737011199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
7.019 × 10⁹⁷(98-digit number)
70193876694841782703…48394687343474022399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.403 × 10⁹⁸(99-digit number)
14038775338968356540…96789374686948044799
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:57,615,569 XPM·at block #6,796,446 · updates every 60s
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