Block #366,581

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 1/19/2014, 12:01:13 PM · Difficulty 10.4334 · 6,436,774 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
8d0f6d6788e14b2e76b95de27697180c8d18ce3f8be99209e1ba82bb4bb18e50

Height

#366,581

Difficulty

10.433421

Transactions

5

Size

1.09 KB

Version

2

Bits

0a6ef4b2

Nonce

2,555

Timestamp

1/19/2014, 12:01:13 PM

Confirmations

6,436,774

Merkle Root

01565fb48b53743184dcda66b0a5790de2c6d852570b9da809c84b244461667c
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.

1.262 × 10¹⁰⁴(105-digit number)
12625364231700306392…94522341839806136319
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
1.262 × 10¹⁰⁴(105-digit number)
12625364231700306392…94522341839806136319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
2.525 × 10¹⁰⁴(105-digit number)
25250728463400612784…89044683679612272639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
5.050 × 10¹⁰⁴(105-digit number)
50501456926801225569…78089367359224545279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.010 × 10¹⁰⁵(106-digit number)
10100291385360245113…56178734718449090559
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
2.020 × 10¹⁰⁵(106-digit number)
20200582770720490227…12357469436898181119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
4.040 × 10¹⁰⁵(106-digit number)
40401165541440980455…24714938873796362239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
8.080 × 10¹⁰⁵(106-digit number)
80802331082881960910…49429877747592724479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.616 × 10¹⁰⁶(107-digit number)
16160466216576392182…98859755495185448959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
3.232 × 10¹⁰⁶(107-digit number)
32320932433152784364…97719510990370897919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
6.464 × 10¹⁰⁶(107-digit number)
64641864866305568728…95439021980741795839
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:57,670,875 XPM·at block #6,803,354 · updates every 60s
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