Block #460,066

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 3/25/2014, 5:57:55 PM · Difficulty 10.4198 · 6,336,538 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
e12259af04f1c79eb1d04235dc2a33b3a8ffe609b0b9ea0313a2d98a070ff6c0

Height

#460,066

Difficulty

10.419836

Transactions

6

Size

1.83 KB

Version

2

Bits

0a6b7a5d

Nonce

281,340

Timestamp

3/25/2014, 5:57:55 PM

Confirmations

6,336,538

Merkle Root

fc5b9c5fd42c00ccc946f08deff1377353512379a331319e296d66ca50433be7
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.

2.528 × 10¹⁰²(103-digit number)
25281785020823600956…15298819617378831801
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
2.528 × 10¹⁰²(103-digit number)
25281785020823600956…15298819617378831801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
5.056 × 10¹⁰²(103-digit number)
50563570041647201912…30597639234757663601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.011 × 10¹⁰³(104-digit number)
10112714008329440382…61195278469515327201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
2.022 × 10¹⁰³(104-digit number)
20225428016658880765…22390556939030654401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
4.045 × 10¹⁰³(104-digit number)
40450856033317761530…44781113878061308801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
8.090 × 10¹⁰³(104-digit number)
80901712066635523060…89562227756122617601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
1.618 × 10¹⁰⁴(105-digit number)
16180342413327104612…79124455512245235201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
3.236 × 10¹⁰⁴(105-digit number)
32360684826654209224…58248911024490470401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
6.472 × 10¹⁰⁴(105-digit number)
64721369653308418448…16497822048980940801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
1.294 × 10¹⁰⁵(106-digit number)
12944273930661683689…32995644097961881601
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:57,616,835 XPM·at block #6,796,603 · updates every 60s
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