Block #56,035

1CCLength 8★☆☆☆☆

Cunningham Chain of the First Kind · Discovered 7/17/2013, 5:25:02 AM · Difficulty 8.9461 · 6,735,383 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
523b3cd6c8304b142a28280a565a796a79110ee263ed4b377534070264c63160

Height

#56,035

Difficulty

8.946057

Transactions

3

Size

2.71 KB

Version

2

Bits

08f230d0

Nonce

1,276

Timestamp

7/17/2013, 5:25:02 AM

Confirmations

6,735,383

Merkle Root

ff13c89bc1ddabf42298eb79442a7dfff8b588bd8172d72b69b356b0f11d48c2
Transactions (3)
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.

1.100 × 10¹⁰³(104-digit number)
11005618999659863460…36048097754379384799
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
1.100 × 10¹⁰³(104-digit number)
11005618999659863460…36048097754379384799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
2.201 × 10¹⁰³(104-digit number)
22011237999319726921…72096195508758769599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
4.402 × 10¹⁰³(104-digit number)
44022475998639453843…44192391017517539199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
8.804 × 10¹⁰³(104-digit number)
88044951997278907686…88384782035035078399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.760 × 10¹⁰⁴(105-digit number)
17608990399455781537…76769564070070156799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
3.521 × 10¹⁰⁴(105-digit number)
35217980798911563074…53539128140140313599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
7.043 × 10¹⁰⁴(105-digit number)
70435961597823126149…07078256280280627199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.408 × 10¹⁰⁵(106-digit number)
14087192319564625229…14156512560561254399
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 8 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 8

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:57,575,281 XPM·at block #6,791,417 · updates every 60s
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