Block #512,817

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 4/27/2014, 3:08:41 AM · Difficulty 10.8340 · 6,283,359 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
b7dc6445e55b4fdd6dd334bf5d2af13c94f8a66cf2c5901cfd006579da7f1b14

Height

#512,817

Difficulty

10.834043

Transactions

1

Size

799 B

Version

2

Bits

0ad583d3

Nonce

97,427

Timestamp

4/27/2014, 3:08:41 AM

Confirmations

6,283,359

Merkle Root

dc2c87e4e02328d9c95828a811edcaeeea2ed0255b0924e57038f2364d678023
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.

7.965 × 10⁹⁵(96-digit number)
79655166183444491328…66257623419719384959
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
7.965 × 10⁹⁵(96-digit number)
79655166183444491328…66257623419719384959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.593 × 10⁹⁶(97-digit number)
15931033236688898265…32515246839438769919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
3.186 × 10⁹⁶(97-digit number)
31862066473377796531…65030493678877539839
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
6.372 × 10⁹⁶(97-digit number)
63724132946755593062…30060987357755079679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.274 × 10⁹⁷(98-digit number)
12744826589351118612…60121974715510159359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
2.548 × 10⁹⁷(98-digit number)
25489653178702237225…20243949431020318719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
5.097 × 10⁹⁷(98-digit number)
50979306357404474450…40487898862040637439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.019 × 10⁹⁸(99-digit number)
10195861271480894890…80975797724081274879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
2.039 × 10⁹⁸(99-digit number)
20391722542961789780…61951595448162549759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
4.078 × 10⁹⁸(99-digit number)
40783445085923579560…23903190896325099519
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:57,613,407 XPM·at block #6,796,175 · updates every 60s
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