Block #132,684

1CCLength 9★☆☆☆☆

Cunningham Chain of the First Kind · Discovered 8/25/2013, 2:07:49 AM · Difficulty 9.7897 · 6,657,314 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
b782c49d939ea002f25832d9907d5b989e9920b8dd91f8c100ebf94074da4c57

Height

#132,684

Difficulty

9.789661

Transactions

12

Size

2.76 KB

Version

2

Bits

09ca273e

Nonce

374,700

Timestamp

8/25/2013, 2:07:49 AM

Confirmations

6,657,314

Merkle Root

a25f231ca69c07311a5d54611c4aa8ee8382e49f9465af5bca8ea77b01debf3c
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.

4.372 × 10⁹⁴(95-digit number)
43729280414053847339…84126306269757058559
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
4.372 × 10⁹⁴(95-digit number)
43729280414053847339…84126306269757058559
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
8.745 × 10⁹⁴(95-digit number)
87458560828107694678…68252612539514117119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.749 × 10⁹⁵(96-digit number)
17491712165621538935…36505225079028234239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
3.498 × 10⁹⁵(96-digit number)
34983424331243077871…73010450158056468479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
6.996 × 10⁹⁵(96-digit number)
69966848662486155742…46020900316112936959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.399 × 10⁹⁶(97-digit number)
13993369732497231148…92041800632225873919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
2.798 × 10⁹⁶(97-digit number)
27986739464994462297…84083601264451747839
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
5.597 × 10⁹⁶(97-digit number)
55973478929988924594…68167202528903495679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.119 × 10⁹⁷(98-digit number)
11194695785997784918…36334405057806991359
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 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
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 1CC formula:

1CC: p₁ (first prime), p₂ = 2p₁ + 1, p₃ = 2p₂ + 1, …
Circulating Supply:57,563,966 XPM·at block #6,789,997 · updates every 60s