Block #59,854

2CCLength 8★☆☆☆☆

Cunningham Chain of the Second Kind · Discovered 7/18/2013, 4:41:43 AM · Difficulty 8.9667 · 6,729,715 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
47a055c66062d7bdf8e18facb6c0b08be1db87dc239747ba48eff492f673d54d

Height

#59,854

Difficulty

8.966734

Transactions

2

Size

1.08 KB

Version

2

Bits

08f77bde

Nonce

0

Timestamp

7/18/2013, 4:41:43 AM

Confirmations

6,729,715

Merkle Root

3f5d0d16dfc007c2461db7750daa946e3a028ac646f84b2261a8521f8c29ac9d
Transactions (2)
1 in → 1 out12.4400 XPM110 B
7 in → 1 out200.0000 XPM907 B
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.

1.202 × 10⁹⁸(99-digit number)
12024159637729225144…00069939409529906351
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
1.202 × 10⁹⁸(99-digit number)
12024159637729225144…00069939409529906351
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
2.404 × 10⁹⁸(99-digit number)
24048319275458450288…00139878819059812701
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
4.809 × 10⁹⁸(99-digit number)
48096638550916900576…00279757638119625401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
9.619 × 10⁹⁸(99-digit number)
96193277101833801153…00559515276239250801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.923 × 10⁹⁹(100-digit number)
19238655420366760230…01119030552478501601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
3.847 × 10⁹⁹(100-digit number)
38477310840733520461…02238061104957003201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
7.695 × 10⁹⁹(100-digit number)
76954621681467040922…04476122209914006401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.539 × 10¹⁰⁰(101-digit number)
15390924336293408184…08952244419828012801
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 8 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 8

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:57,560,513 XPM·at block #6,789,568 · updates every 60s