Block #364,644

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 1/18/2014, 5:20:56 AM · Difficulty 10.4213 · 6,431,194 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
f0b8b4cdc2461daa7d3346106720560caa42fe45dd1c3080a761cf49c782fdcd

Height

#364,644

Difficulty

10.421332

Transactions

11

Size

3.68 KB

Version

2

Bits

0a6bdc6e

Nonce

7,870

Timestamp

1/18/2014, 5:20:56 AM

Confirmations

6,431,194

Merkle Root

71834bc5b1788047bda1cb5c8f92235d08fc921462018d1602f9a2b96c333759
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.

3.822 × 10¹⁰¹(102-digit number)
38226775870671331484…30386278237918986239
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
3.822 × 10¹⁰¹(102-digit number)
38226775870671331484…30386278237918986239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
7.645 × 10¹⁰¹(102-digit number)
76453551741342662968…60772556475837972479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.529 × 10¹⁰²(103-digit number)
15290710348268532593…21545112951675944959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
3.058 × 10¹⁰²(103-digit number)
30581420696537065187…43090225903351889919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
6.116 × 10¹⁰²(103-digit number)
61162841393074130374…86180451806703779839
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.223 × 10¹⁰³(104-digit number)
12232568278614826074…72360903613407559679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
2.446 × 10¹⁰³(104-digit number)
24465136557229652149…44721807226815119359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
4.893 × 10¹⁰³(104-digit number)
48930273114459304299…89443614453630238719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
9.786 × 10¹⁰³(104-digit number)
97860546228918608599…78887228907260477439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.957 × 10¹⁰⁴(105-digit number)
19572109245783721719…57774457814520954879
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:57,610,787 XPM·at block #6,795,837 · updates every 60s
xpmprime.info is a work in progress. If you enjoy using this service you can support this project with a Primecoin donation.