Block #461,875

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 3/27/2014, 1:11:49 AM · Difficulty 10.4133 · 6,341,439 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
024c8c9032d6d98ad7a3e6a19b1f1402de902aa604c643684d47485a8419b7e5

Height

#461,875

Difficulty

10.413267

Transactions

1

Size

1004 B

Version

2

Bits

0a69cbde

Nonce

100,301

Timestamp

3/27/2014, 1:11:49 AM

Confirmations

6,341,439

Merkle Root

2807be379318647d047bad0800c3cc7d311fe29696bccef661f4e6ddbf3f73bf
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.

4.056 × 10⁹⁶(97-digit number)
40563300933843594491…96458548920052286399
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
4.056 × 10⁹⁶(97-digit number)
40563300933843594491…96458548920052286399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
8.112 × 10⁹⁶(97-digit number)
81126601867687188982…92917097840104572799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.622 × 10⁹⁷(98-digit number)
16225320373537437796…85834195680209145599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
3.245 × 10⁹⁷(98-digit number)
32450640747074875592…71668391360418291199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
6.490 × 10⁹⁷(98-digit number)
64901281494149751185…43336782720836582399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.298 × 10⁹⁸(99-digit number)
12980256298829950237…86673565441673164799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
2.596 × 10⁹⁸(99-digit number)
25960512597659900474…73347130883346329599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
5.192 × 10⁹⁸(99-digit number)
51921025195319800948…46694261766692659199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.038 × 10⁹⁹(100-digit number)
10384205039063960189…93388523533385318399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
2.076 × 10⁹⁹(100-digit number)
20768410078127920379…86777047066770636799
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:57,670,541 XPM·at block #6,803,313 · updates every 60s
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