Block #364,928

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 1/18/2014, 9:55:34 AM · Difficulty 10.4230 · 6,437,281 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
aa3c6057915c20d4a44bdff685937bda48cdabcbf8aac707b39174133f40169f

Height

#364,928

Difficulty

10.423011

Transactions

2

Size

853 B

Version

2

Bits

0a6c4a75

Nonce

56,960

Timestamp

1/18/2014, 9:55:34 AM

Confirmations

6,437,281

Merkle Root

3f67279a2d2691a58fcb7c76422783d9c034328c37e72c52618cf45618e72c9d
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.

6.424 × 10¹⁰⁰(101-digit number)
64246289939480575966…76716401622564957101
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
6.424 × 10¹⁰⁰(101-digit number)
64246289939480575966…76716401622564957101
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.284 × 10¹⁰¹(102-digit number)
12849257987896115193…53432803245129914201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
2.569 × 10¹⁰¹(102-digit number)
25698515975792230386…06865606490259828401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
5.139 × 10¹⁰¹(102-digit number)
51397031951584460773…13731212980519656801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.027 × 10¹⁰²(103-digit number)
10279406390316892154…27462425961039313601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
2.055 × 10¹⁰²(103-digit number)
20558812780633784309…54924851922078627201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
4.111 × 10¹⁰²(103-digit number)
41117625561267568618…09849703844157254401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
8.223 × 10¹⁰²(103-digit number)
82235251122535137236…19699407688314508801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.644 × 10¹⁰³(104-digit number)
16447050224507027447…39398815376629017601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
3.289 × 10¹⁰³(104-digit number)
32894100449014054894…78797630753258035201
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:57,661,676 XPM·at block #6,802,208 · updates every 60s
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