Block #93,994

1CCLength 9★☆☆☆☆

Cunningham Chain of the First Kind · Discovered 8/2/2013, 7:17:05 PM · Difficulty 9.2013 · 6,700,372 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
23b425a65599e336e33ce1d2b13eaf0ec7debd4fd1eba7ffd4b0c7bcfeb6e8e9

Height

#93,994

Difficulty

9.201252

Transactions

6

Size

2.97 KB

Version

2

Bits

09338539

Nonce

54,786

Timestamp

8/2/2013, 7:17:05 PM

Confirmations

6,700,372

Merkle Root

8fb353c0e2f670c01a2414509ed79d264576bd5653d9dc80c7d5b4bb82514a82
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.

4.313 × 10¹⁰⁶(107-digit number)
43139825718774230638…62783577752838546349
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
4.313 × 10¹⁰⁶(107-digit number)
43139825718774230638…62783577752838546349
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
8.627 × 10¹⁰⁶(107-digit number)
86279651437548461277…25567155505677092699
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.725 × 10¹⁰⁷(108-digit number)
17255930287509692255…51134311011354185399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
3.451 × 10¹⁰⁷(108-digit number)
34511860575019384510…02268622022708370799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
6.902 × 10¹⁰⁷(108-digit number)
69023721150038769021…04537244045416741599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.380 × 10¹⁰⁸(109-digit number)
13804744230007753804…09074488090833483199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
2.760 × 10¹⁰⁸(109-digit number)
27609488460015507608…18148976181666966399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
5.521 × 10¹⁰⁸(109-digit number)
55218976920031015217…36297952363333932799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.104 × 10¹⁰⁹(110-digit number)
11043795384006203043…72595904726667865599
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 9 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
CommonChain length 9

Found in most blocks. The baseline for Primecoin's proof-of-work.

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:57,598,962 XPM·at block #6,794,365 · updates every 60s
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