Block #144,028

1CCLength 9★☆☆☆☆

Cunningham Chain of the First Kind · Discovered 9/1/2013, 1:42:20 AM · Difficulty 9.8374 · 6,648,323 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
8eb2b2284b14ea9b831bd55bb05864c3e0e22dc662ce75689d3e3b4665609d5a

Height

#144,028

Difficulty

9.837436

Transactions

11

Size

3.26 KB

Version

2

Bits

09d66238

Nonce

34,916

Timestamp

9/1/2013, 1:42:20 AM

Confirmations

6,648,323

Merkle Root

dfd6c0490d23bcf5fe4ebc9076fe835abd71fee9dbf437fc81c4f0eee9b5bdac
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.

3.237 × 10⁹³(94-digit number)
32372045253507099125…67735293723786006799
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
3.237 × 10⁹³(94-digit number)
32372045253507099125…67735293723786006799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
6.474 × 10⁹³(94-digit number)
64744090507014198250…35470587447572013599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.294 × 10⁹⁴(95-digit number)
12948818101402839650…70941174895144027199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
2.589 × 10⁹⁴(95-digit number)
25897636202805679300…41882349790288054399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
5.179 × 10⁹⁴(95-digit number)
51795272405611358600…83764699580576108799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.035 × 10⁹⁵(96-digit number)
10359054481122271720…67529399161152217599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
2.071 × 10⁹⁵(96-digit number)
20718108962244543440…35058798322304435199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
4.143 × 10⁹⁵(96-digit number)
41436217924489086880…70117596644608870399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
8.287 × 10⁹⁵(96-digit number)
82872435848978173760…40235193289217740799
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 9 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
CommonChain length 9

Found in most blocks. The baseline for Primecoin's proof-of-work.

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:57,582,772 XPM·at block #6,792,350 · 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.