Block #450,579

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 3/19/2014, 9:35:32 AM · Difficulty 10.3722 · 6,348,632 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
a45aeefe4686bef5e7dee347e2ca24325ae9277e094b173a41c114f95d189d34

Height

#450,579

Difficulty

10.372198

Transactions

2

Size

683 B

Version

2

Bits

0a5f4864

Nonce

150,526

Timestamp

3/19/2014, 9:35:32 AM

Confirmations

6,348,632

Merkle Root

929af3107e51818d11e8fd75af60536a36008855f6d67b41f10e5c67782e715a
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.

2.589 × 10⁹⁴(95-digit number)
25895480002270617442…48407842962121338881
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
2.589 × 10⁹⁴(95-digit number)
25895480002270617442…48407842962121338881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
5.179 × 10⁹⁴(95-digit number)
51790960004541234884…96815685924242677761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.035 × 10⁹⁵(96-digit number)
10358192000908246976…93631371848485355521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
2.071 × 10⁹⁵(96-digit number)
20716384001816493953…87262743696970711041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
4.143 × 10⁹⁵(96-digit number)
41432768003632987907…74525487393941422081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
8.286 × 10⁹⁵(96-digit number)
82865536007265975814…49050974787882844161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
1.657 × 10⁹⁶(97-digit number)
16573107201453195162…98101949575765688321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
3.314 × 10⁹⁶(97-digit number)
33146214402906390325…96203899151531376641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
6.629 × 10⁹⁶(97-digit number)
66292428805812780651…92407798303062753281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
1.325 × 10⁹⁷(98-digit number)
13258485761162556130…84815596606125506561
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 Second 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 2CC formula:

2CC: p₁ (first prime), p₂ = 2p₁ − 1, p₃ = 2p₂ − 1, …
Circulating Supply:57,637,728 XPM·at block #6,799,210 · updates every 60s
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