Block #332,551

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 12/28/2013, 3:29:46 AM · Difficulty 10.1699 · 6,462,786 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
1f31e22379180dacb2ece9621516c229c79513b5c0c69b0e5c571fbacf845417

Height

#332,551

Difficulty

10.169933

Transactions

11

Size

6.34 KB

Version

2

Bits

0a2b80b3

Nonce

15,775

Timestamp

12/28/2013, 3:29:46 AM

Confirmations

6,462,786

Merkle Root

8bceca8a51a54d9cc55b07b5cb39687f381f0936a0aebcefc9f62987640928b6
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.

2.293 × 10¹⁰⁰(101-digit number)
22932863368928756731…09637591588611458561
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
2.293 × 10¹⁰⁰(101-digit number)
22932863368928756731…09637591588611458561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
4.586 × 10¹⁰⁰(101-digit number)
45865726737857513463…19275183177222917121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
9.173 × 10¹⁰⁰(101-digit number)
91731453475715026927…38550366354445834241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.834 × 10¹⁰¹(102-digit number)
18346290695143005385…77100732708891668481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
3.669 × 10¹⁰¹(102-digit number)
36692581390286010771…54201465417783336961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
7.338 × 10¹⁰¹(102-digit number)
73385162780572021542…08402930835566673921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
1.467 × 10¹⁰²(103-digit number)
14677032556114404308…16805861671133347841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
2.935 × 10¹⁰²(103-digit number)
29354065112228808616…33611723342266695681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
5.870 × 10¹⁰²(103-digit number)
58708130224457617233…67223446684533391361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
1.174 × 10¹⁰³(104-digit number)
11741626044891523446…34446893369066782721
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:57,606,755 XPM·at block #6,795,336 · updates every 60s
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