Block #59,734

2CCLength 8★☆☆☆☆

Cunningham Chain of the Second Kind · Discovered 7/18/2013, 3:59:05 AM · Difficulty 8.9662 · 6,735,838 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
64fd207300f5585f35fd62f48f0e261cddffc36643a31be87d686beefb27242f

Height

#59,734

Difficulty

8.966215

Transactions

4

Size

881 B

Version

2

Bits

08f759d6

Nonce

218

Timestamp

7/18/2013, 3:59:05 AM

Confirmations

6,735,838

Merkle Root

89ff9c4181b43a1472c37de5b8e37496fb04324a8c307cc229fcc1dc0897e95a
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.

7.819 × 10⁹⁸(99-digit number)
78192578706895339837…75249102248763167681
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
7.819 × 10⁹⁸(99-digit number)
78192578706895339837…75249102248763167681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.563 × 10⁹⁹(100-digit number)
15638515741379067967…50498204497526335361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
3.127 × 10⁹⁹(100-digit number)
31277031482758135935…00996408995052670721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
6.255 × 10⁹⁹(100-digit number)
62554062965516271870…01992817990105341441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.251 × 10¹⁰⁰(101-digit number)
12510812593103254374…03985635980210682881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
2.502 × 10¹⁰⁰(101-digit number)
25021625186206508748…07971271960421365761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
5.004 × 10¹⁰⁰(101-digit number)
50043250372413017496…15942543920842731521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.000 × 10¹⁰¹(102-digit number)
10008650074482603499…31885087841685463041
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:57,608,636 XPM·at block #6,795,571 · updates every 60s
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