Block #460,688

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 3/26/2014, 5:11:38 AM · Difficulty 10.4145 · 6,338,765 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
ec4cbbf04e11e947772ef5b703fc539f8eb043e627f839322e80f19a22c80df3

Height

#460,688

Difficulty

10.414513

Transactions

8

Size

4.43 KB

Version

2

Bits

0a6a1d84

Nonce

4,925

Timestamp

3/26/2014, 5:11:38 AM

Confirmations

6,338,765

Merkle Root

0e6ebdb1757d20a83d099e93e8f04a20a84fbff0d90591dd2d39736abb6f0c3d
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.

6.851 × 10⁹²(93-digit number)
68513226714850318505…12948534026645389499
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
6.851 × 10⁹²(93-digit number)
68513226714850318505…12948534026645389499
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.370 × 10⁹³(94-digit number)
13702645342970063701…25897068053290778999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
2.740 × 10⁹³(94-digit number)
27405290685940127402…51794136106581557999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
5.481 × 10⁹³(94-digit number)
54810581371880254804…03588272213163115999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.096 × 10⁹⁴(95-digit number)
10962116274376050960…07176544426326231999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
2.192 × 10⁹⁴(95-digit number)
21924232548752101921…14353088852652463999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
4.384 × 10⁹⁴(95-digit number)
43848465097504203843…28706177705304927999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
8.769 × 10⁹⁴(95-digit number)
87696930195008407687…57412355410609855999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.753 × 10⁹⁵(96-digit number)
17539386039001681537…14824710821219711999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
3.507 × 10⁹⁵(96-digit number)
35078772078003363074…29649421642439423999
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:57,639,675 XPM·at block #6,799,452 · updates every 60s
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