Block #345,107

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 1/5/2014, 5:15:50 PM · Difficulty 10.2086 · 6,453,923 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
b64ed2a6b3b194f6321c727e45cad40bdf8ee94b1e23aa6a1de096dd5b2676fe

Height

#345,107

Difficulty

10.208626

Transactions

4

Size

1.67 KB

Version

2

Bits

0a356889

Nonce

14,958

Timestamp

1/5/2014, 5:15:50 PM

Confirmations

6,453,923

Merkle Root

87cfd7ab23f0f9fe466b984b6641e12e81513c3c3bbe9a09af3e4003d3ada0f2
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.

2.162 × 10⁹³(94-digit number)
21624802276564714235…46011312457068321499
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
2.162 × 10⁹³(94-digit number)
21624802276564714235…46011312457068321499
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
4.324 × 10⁹³(94-digit number)
43249604553129428471…92022624914136642999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
8.649 × 10⁹³(94-digit number)
86499209106258856942…84045249828273285999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.729 × 10⁹⁴(95-digit number)
17299841821251771388…68090499656546571999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
3.459 × 10⁹⁴(95-digit number)
34599683642503542777…36180999313093143999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
6.919 × 10⁹⁴(95-digit number)
69199367285007085554…72361998626186287999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.383 × 10⁹⁵(96-digit number)
13839873457001417110…44723997252372575999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
2.767 × 10⁹⁵(96-digit number)
27679746914002834221…89447994504745151999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
5.535 × 10⁹⁵(96-digit number)
55359493828005668443…78895989009490303999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.107 × 10⁹⁶(97-digit number)
11071898765601133688…57791978018980607999
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:57,636,278 XPM·at block #6,799,029 · updates every 60s
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