Block #459,416

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 3/25/2014, 7:29:09 AM · Difficulty 10.4170 · 6,346,500 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
23ebc959e28be6de13057c7b36819e0ed9c06be885288c66538547cce371ff6f

Height

#459,416

Difficulty

10.417009

Transactions

7

Size

2.50 KB

Version

2

Bits

0a6ac11e

Nonce

206,241

Timestamp

3/25/2014, 7:29:09 AM

Confirmations

6,346,500

Merkle Root

729de333dfc4b413777d2741680317af6f0fcfd9f128def89917fe0ee0a5fd0f
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.

3.653 × 10⁹⁷(98-digit number)
36531466248984193686…18473941260805609361
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
3.653 × 10⁹⁷(98-digit number)
36531466248984193686…18473941260805609361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
7.306 × 10⁹⁷(98-digit number)
73062932497968387373…36947882521611218721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.461 × 10⁹⁸(99-digit number)
14612586499593677474…73895765043222437441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
2.922 × 10⁹⁸(99-digit number)
29225172999187354949…47791530086444874881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
5.845 × 10⁹⁸(99-digit number)
58450345998374709898…95583060172889749761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.169 × 10⁹⁹(100-digit number)
11690069199674941979…91166120345779499521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
2.338 × 10⁹⁹(100-digit number)
23380138399349883959…82332240691558999041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
4.676 × 10⁹⁹(100-digit number)
46760276798699767919…64664481383117998081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
9.352 × 10⁹⁹(100-digit number)
93520553597399535838…29328962766235996161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
1.870 × 10¹⁰⁰(101-digit number)
18704110719479907167…58657925532471992321
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 10 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
UncommonChain length 10

Roughly 1 in 100 blocks. Solid but expected in a healthy network.

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:57,691,418 XPM·at block #6,805,915 · updates every 60s
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