Block #460,954

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 3/26/2014, 9:26:37 AM · Difficulty 10.4167 · 6,334,099 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
9c814376672989c323b8f81883ad59fc56de5aa12c08afa09cf04370b66bc53d

Height

#460,954

Difficulty

10.416693

Transactions

13

Size

85.96 KB

Version

2

Bits

0a6aac5d

Nonce

819,885

Timestamp

3/26/2014, 9:26:37 AM

Confirmations

6,334,099

Merkle Root

4d562cd248e20d2eb647598458948fba366414d8c1760983c6469b52d8675b5f
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.

4.085 × 10¹⁰³(104-digit number)
40854426903851019186…05124405268063868801
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
4.085 × 10¹⁰³(104-digit number)
40854426903851019186…05124405268063868801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
8.170 × 10¹⁰³(104-digit number)
81708853807702038372…10248810536127737601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.634 × 10¹⁰⁴(105-digit number)
16341770761540407674…20497621072255475201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
3.268 × 10¹⁰⁴(105-digit number)
32683541523080815349…40995242144510950401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
6.536 × 10¹⁰⁴(105-digit number)
65367083046161630698…81990484289021900801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.307 × 10¹⁰⁵(106-digit number)
13073416609232326139…63980968578043801601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
2.614 × 10¹⁰⁵(106-digit number)
26146833218464652279…27961937156087603201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
5.229 × 10¹⁰⁵(106-digit number)
52293666436929304558…55923874312175206401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.045 × 10¹⁰⁶(107-digit number)
10458733287385860911…11847748624350412801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
2.091 × 10¹⁰⁶(107-digit number)
20917466574771721823…23695497248700825601
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:57,604,464 XPM·at block #6,795,052 · updates every 60s
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