Block #326,584

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 12/23/2013, 10:08:30 PM · Difficulty 10.1870 · 6,480,382 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
2a0a1f58156a987c9944b1cc8c0705acbf47d03ec5e0a6a8c063f9021938094e

Height

#326,584

Difficulty

10.186974

Transactions

12

Size

3.73 KB

Version

2

Bits

0a2fdd86

Nonce

32,311

Timestamp

12/23/2013, 10:08:30 PM

Confirmations

6,480,382

Merkle Root

24a456f271a216753c408b01132ee0ad98b879a0bbe74a932fa556437b7a6e18
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.

7.311 × 10¹⁰¹(102-digit number)
73115950007800001424…21589275478031052801
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
7.311 × 10¹⁰¹(102-digit number)
73115950007800001424…21589275478031052801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.462 × 10¹⁰²(103-digit number)
14623190001560000284…43178550956062105601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
2.924 × 10¹⁰²(103-digit number)
29246380003120000569…86357101912124211201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
5.849 × 10¹⁰²(103-digit number)
58492760006240001139…72714203824248422401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.169 × 10¹⁰³(104-digit number)
11698552001248000227…45428407648496844801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
2.339 × 10¹⁰³(104-digit number)
23397104002496000455…90856815296993689601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
4.679 × 10¹⁰³(104-digit number)
46794208004992000911…81713630593987379201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
9.358 × 10¹⁰³(104-digit number)
93588416009984001823…63427261187974758401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.871 × 10¹⁰⁴(105-digit number)
18717683201996800364…26854522375949516801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
3.743 × 10¹⁰⁴(105-digit number)
37435366403993600729…53709044751899033601
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:57,699,827 XPM·at block #6,806,965 · updates every 60s
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