Block #372,744

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 1/23/2014, 7:57:48 PM · Difficulty 10.4268 · 6,430,929 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
09c44017c12b055633869818263e68d617272c3e155d467484780bb1d44684b3

Height

#372,744

Difficulty

10.426826

Transactions

3

Size

1.67 KB

Version

2

Bits

0a6d4473

Nonce

269,060

Timestamp

1/23/2014, 7:57:48 PM

Confirmations

6,430,929

Merkle Root

9d441a8c29f503be0c6fcb4246e98f1251b89595760d6162f370142ec0047725
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.

4.283 × 10¹⁰⁰(101-digit number)
42831044565130339385…32776667032886157559
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
4.283 × 10¹⁰⁰(101-digit number)
42831044565130339385…32776667032886157559
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
8.566 × 10¹⁰⁰(101-digit number)
85662089130260678771…65553334065772315119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.713 × 10¹⁰¹(102-digit number)
17132417826052135754…31106668131544630239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
3.426 × 10¹⁰¹(102-digit number)
34264835652104271508…62213336263089260479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
6.852 × 10¹⁰¹(102-digit number)
68529671304208543017…24426672526178520959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.370 × 10¹⁰²(103-digit number)
13705934260841708603…48853345052357041919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
2.741 × 10¹⁰²(103-digit number)
27411868521683417206…97706690104714083839
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
5.482 × 10¹⁰²(103-digit number)
54823737043366834413…95413380209428167679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.096 × 10¹⁰³(104-digit number)
10964747408673366882…90826760418856335359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
2.192 × 10¹⁰³(104-digit number)
21929494817346733765…81653520837712670719
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:57,673,421 XPM·at block #6,803,672 · updates every 60s
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