Block #448,635

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 3/18/2014, 1:59:41 AM · Difficulty 10.3651 · 6,357,520 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
b92690ef4d95b2af9dd1754bfcb2957ba27889e1af9051290e675d0c237f255c

Height

#448,635

Difficulty

10.365081

Transactions

4

Size

899 B

Version

2

Bits

0a5d75f8

Nonce

185,909

Timestamp

3/18/2014, 1:59:41 AM

Confirmations

6,357,520

Merkle Root

04ecaa9195a2bec1de7967d2eb170c643f9604087f8ffc97e714e5adc55dc97f
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.

1.079 × 10⁹⁷(98-digit number)
10796968995090970818…13633149743649511039
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
1.079 × 10⁹⁷(98-digit number)
10796968995090970818…13633149743649511039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
2.159 × 10⁹⁷(98-digit number)
21593937990181941637…27266299487299022079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
4.318 × 10⁹⁷(98-digit number)
43187875980363883275…54532598974598044159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
8.637 × 10⁹⁷(98-digit number)
86375751960727766550…09065197949196088319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.727 × 10⁹⁸(99-digit number)
17275150392145553310…18130395898392176639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
3.455 × 10⁹⁸(99-digit number)
34550300784291106620…36260791796784353279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
6.910 × 10⁹⁸(99-digit number)
69100601568582213240…72521583593568706559
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.382 × 10⁹⁹(100-digit number)
13820120313716442648…45043167187137413119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
2.764 × 10⁹⁹(100-digit number)
27640240627432885296…90086334374274826239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
5.528 × 10⁹⁹(100-digit number)
55280481254865770592…80172668748549652479
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:57,693,321 XPM·at block #6,806,154 · 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.