Block #744,323

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 9/28/2014, 4:02:02 AM · Difficulty 10.9795 · 6,051,652 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
4a614e8e8cb87da2b4eefc6f8865dbb72f8365bd8090a7ca1c6fe0df9b54853f

Height

#744,323

Difficulty

10.979539

Transactions

4

Size

1.73 KB

Version

2

Bits

0afac30b

Nonce

690,845,672

Timestamp

9/28/2014, 4:02:02 AM

Confirmations

6,051,652

Merkle Root

cdf9db102c0eb7fb60e61d03d3a24e696bb7d67e011b399feea977ba5d09dbc1
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.

2.954 × 10⁹⁵(96-digit number)
29548658871114464644…25064027261707716479
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
2.954 × 10⁹⁵(96-digit number)
29548658871114464644…25064027261707716479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
5.909 × 10⁹⁵(96-digit number)
59097317742228929289…50128054523415432959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.181 × 10⁹⁶(97-digit number)
11819463548445785857…00256109046830865919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
2.363 × 10⁹⁶(97-digit number)
23638927096891571715…00512218093661731839
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
4.727 × 10⁹⁶(97-digit number)
47277854193783143431…01024436187323463679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
9.455 × 10⁹⁶(97-digit number)
94555708387566286863…02048872374646927359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.891 × 10⁹⁷(98-digit number)
18911141677513257372…04097744749293854719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
3.782 × 10⁹⁷(98-digit number)
37822283355026514745…08195489498587709439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
7.564 × 10⁹⁷(98-digit number)
75644566710053029490…16390978997175418879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.512 × 10⁹⁸(99-digit number)
15128913342010605898…32781957994350837759
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:57,611,893 XPM·at block #6,795,974 · 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.