Block #292,031

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 12/3/2013, 12:36:13 PM · Difficulty 9.9901 · 6,503,273 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
252515155f2f856fb2b7ccd314bc4bfbe582b25d07014dd5e48b37ec5dbf71e3

Height

#292,031

Difficulty

9.990103

Transactions

7

Size

3.77 KB

Version

2

Bits

09fd775d

Nonce

13,975

Timestamp

12/3/2013, 12:36:13 PM

Confirmations

6,503,273

Merkle Root

2313dd9e4da7551af7c69b660a935110ed770d3f9ea3a92307128fad6aa9f485
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.

3.622 × 10⁹⁷(98-digit number)
36220898676126812968…49867077358574131199
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
3.622 × 10⁹⁷(98-digit number)
36220898676126812968…49867077358574131199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
7.244 × 10⁹⁷(98-digit number)
72441797352253625936…99734154717148262399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.448 × 10⁹⁸(99-digit number)
14488359470450725187…99468309434296524799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
2.897 × 10⁹⁸(99-digit number)
28976718940901450374…98936618868593049599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
5.795 × 10⁹⁸(99-digit number)
57953437881802900749…97873237737186099199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.159 × 10⁹⁹(100-digit number)
11590687576360580149…95746475474372198399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
2.318 × 10⁹⁹(100-digit number)
23181375152721160299…91492950948744396799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
4.636 × 10⁹⁹(100-digit number)
46362750305442320599…82985901897488793599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
9.272 × 10⁹⁹(100-digit number)
92725500610884641198…65971803794977587199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.854 × 10¹⁰⁰(101-digit number)
18545100122176928239…31943607589955174399
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 First 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 1CC formula:

1CC: p₁ (first prime), p₂ = 2p₁ + 1, p₃ = 2p₂ + 1, …
Circulating Supply:57,606,485 XPM·at block #6,795,303 · updates every 60s
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