Block #366,642

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 1/19/2014, 1:05:42 PM · Difficulty 10.4330 · 6,431,740 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
3b91b6248b3d3a4ee677e1fcdeb32d8de1496aa1ebc0d085d0fca3965066b88b

Height

#366,642

Difficulty

10.433045

Transactions

5

Size

1.41 KB

Version

2

Bits

0a6edc10

Nonce

100,663,370

Timestamp

1/19/2014, 1:05:42 PM

Confirmations

6,431,740

Merkle Root

0d1f8def9b3af2ce79586e365424f286b886af8753348732803bcfb31d49b4f6
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.

2.214 × 10⁹⁶(97-digit number)
22144071215972386494…36324356267699782079
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
2.214 × 10⁹⁶(97-digit number)
22144071215972386494…36324356267699782079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
4.428 × 10⁹⁶(97-digit number)
44288142431944772988…72648712535399564159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
8.857 × 10⁹⁶(97-digit number)
88576284863889545977…45297425070799128319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.771 × 10⁹⁷(98-digit number)
17715256972777909195…90594850141598256639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
3.543 × 10⁹⁷(98-digit number)
35430513945555818391…81189700283196513279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
7.086 × 10⁹⁷(98-digit number)
70861027891111636782…62379400566393026559
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.417 × 10⁹⁸(99-digit number)
14172205578222327356…24758801132786053119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
2.834 × 10⁹⁸(99-digit number)
28344411156444654712…49517602265572106239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
5.668 × 10⁹⁸(99-digit number)
56688822312889309425…99035204531144212479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.133 × 10⁹⁹(100-digit number)
11337764462577861885…98070409062288424959
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:57,631,062 XPM·at block #6,798,381 · 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.