Block #100,453

1CCLength 9★☆☆☆☆

Cunningham Chain of the First Kind · Discovered 8/6/2013, 4:35:42 AM · Difficulty 9.4252 · 6,697,358 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
2c23f1b282b544cf8ef5ba1a713f08bbb1572608b249023b85bdee832199421d

Height

#100,453

Difficulty

9.425217

Transactions

3

Size

2.24 KB

Version

2

Bits

096cdb04

Nonce

27,533

Timestamp

8/6/2013, 4:35:42 AM

Confirmations

6,697,358

Merkle Root

c7723f0a11e532f1a8e78f40b3672db9e4a697ed7c7c931493fb54e77ac8b4be
Transactions (3)
1 in → 1 out11.2700 XPM109 B
16 in → 1 out209.0000 XPM1.82 KB
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.

1.049 × 10⁹⁸(99-digit number)
10499012130086985990…35073828500580157579
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
1.049 × 10⁹⁸(99-digit number)
10499012130086985990…35073828500580157579
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
2.099 × 10⁹⁸(99-digit number)
20998024260173971981…70147657001160315159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
4.199 × 10⁹⁸(99-digit number)
41996048520347943963…40295314002320630319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
8.399 × 10⁹⁸(99-digit number)
83992097040695887926…80590628004641260639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.679 × 10⁹⁹(100-digit number)
16798419408139177585…61181256009282521279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
3.359 × 10⁹⁹(100-digit number)
33596838816278355170…22362512018565042559
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
6.719 × 10⁹⁹(100-digit number)
67193677632556710341…44725024037130085119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.343 × 10¹⁰⁰(101-digit number)
13438735526511342068…89450048074260170239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
2.687 × 10¹⁰⁰(101-digit number)
26877471053022684136…78900096148520340479
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:57,626,466 XPM·at block #6,797,810 · updates every 60s
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