Block #36,434

1CCLength 8★☆☆☆☆

Cunningham Chain of the First Kind · Discovered 7/14/2013, 9:23:52 AM · Difficulty 7.9954 · 6,753,506 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
df8957268c4791f3077519452a3f88446e56939b3e77bcbd806e1d2c1ea518cc

Height

#36,434

Difficulty

7.995373

Transactions

2

Size

360 B

Version

2

Bits

07fed0c2

Nonce

321

Timestamp

7/14/2013, 9:23:52 AM

Confirmations

6,753,506

Merkle Root

d8bd8fcd26fbf083ee906c348d6a7b416865ae7e80d89690ff2c6b7ee3726bd8
Transactions (2)
1 in → 1 out15.6300 XPM109 B
1 in → 1 out15.6300 XPM158 B
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.

6.062 × 10¹⁰¹(102-digit number)
60624992299431885109…01495566264082108159
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
6.062 × 10¹⁰¹(102-digit number)
60624992299431885109…01495566264082108159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.212 × 10¹⁰²(103-digit number)
12124998459886377021…02991132528164216319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
2.424 × 10¹⁰²(103-digit number)
24249996919772754043…05982265056328432639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
4.849 × 10¹⁰²(103-digit number)
48499993839545508087…11964530112656865279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
9.699 × 10¹⁰²(103-digit number)
96999987679091016175…23929060225313730559
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.939 × 10¹⁰³(104-digit number)
19399997535818203235…47858120450627461119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
3.879 × 10¹⁰³(104-digit number)
38799995071636406470…95716240901254922239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
7.759 × 10¹⁰³(104-digit number)
77599990143272812940…91432481802509844479
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:57,563,495 XPM·at block #6,789,939 · updates every 60s