Block #59,429

2CCLength 9★☆☆☆☆

Cunningham Chain of the Second Kind · Discovered 7/18/2013, 2:05:59 AM · Difficulty 8.9649 · 6,735,966 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
305c944dc1d1563bd9c9406d4faccb2a4182b734fc849dd89c60c8a8375c42a8

Height

#59,429

Difficulty

8.964894

Transactions

2

Size

2.80 KB

Version

2

Bits

08f70348

Nonce

86

Timestamp

7/18/2013, 2:05:59 AM

Confirmations

6,735,966

Merkle Root

0e5db28e510fb0f14c7fbb79bbbc63481525a5eee0000489aa070d3a60bc02d0
Transactions (2)
1 in → 1 out12.4600 XPM110 B
23 in → 1 out287.1500 XPM2.60 KB
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.

3.363 × 10¹⁰⁵(106-digit number)
33634861353060123605…24304299715666826731
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
3.363 × 10¹⁰⁵(106-digit number)
33634861353060123605…24304299715666826731
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
6.726 × 10¹⁰⁵(106-digit number)
67269722706120247211…48608599431333653461
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.345 × 10¹⁰⁶(107-digit number)
13453944541224049442…97217198862667306921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
2.690 × 10¹⁰⁶(107-digit number)
26907889082448098884…94434397725334613841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
5.381 × 10¹⁰⁶(107-digit number)
53815778164896197769…88868795450669227681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.076 × 10¹⁰⁷(108-digit number)
10763155632979239553…77737590901338455361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
2.152 × 10¹⁰⁷(108-digit number)
21526311265958479107…55475181802676910721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
4.305 × 10¹⁰⁷(108-digit number)
43052622531916958215…10950363605353821441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
8.610 × 10¹⁰⁷(108-digit number)
86105245063833916430…21900727210707642881
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:57,607,219 XPM·at block #6,795,394 · updates every 60s
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