Block #132,733

2CCLength 9★☆☆☆☆

Cunningham Chain of the Second Kind · Discovered 8/25/2013, 2:45:55 AM · Difficulty 9.7901 · 6,693,852 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
c68317597276dd1b4fbb9d6d63460e66c0094b7620ec293da9541c6900ac1187

Height

#132,733

Difficulty

9.790107

Transactions

10

Size

5.71 KB

Version

2

Bits

09ca4471

Nonce

95,444

Timestamp

8/25/2013, 2:45:55 AM

Confirmations

6,693,852

Merkle Root

679864a2b3e10bfe6c5fb02646104d6bf22528bc581cb0cbcc31b41990daf930
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.

4.780 × 10⁹³(94-digit number)
47808691320115540131…53057782095760952961
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
4.780 × 10⁹³(94-digit number)
47808691320115540131…53057782095760952961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
9.561 × 10⁹³(94-digit number)
95617382640231080263…06115564191521905921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.912 × 10⁹⁴(95-digit number)
19123476528046216052…12231128383043811841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
3.824 × 10⁹⁴(95-digit number)
38246953056092432105…24462256766087623681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
7.649 × 10⁹⁴(95-digit number)
76493906112184864210…48924513532175247361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.529 × 10⁹⁵(96-digit number)
15298781222436972842…97849027064350494721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
3.059 × 10⁹⁵(96-digit number)
30597562444873945684…95698054128700989441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
6.119 × 10⁹⁵(96-digit number)
61195124889747891368…91396108257401978881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.223 × 10⁹⁶(97-digit number)
12239024977949578273…82792216514803957761
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 9 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
CommonChain length 9

Found in most blocks. The baseline for Primecoin's proof-of-work.

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:57,856,830 XPM·at block #6,826,584 · updates every 60s
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