Block #444,257

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 3/15/2014, 3:56:11 AM · Difficulty 10.3406 · 6,361,713 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
dafad27400f4ef50b8b1d2aa58caaf15dc896cd9ae860ccc4793774f8a85790e

Height

#444,257

Difficulty

10.340563

Transactions

2

Size

463 B

Version

2

Bits

0a572f22

Nonce

10,649

Timestamp

3/15/2014, 3:56:11 AM

Confirmations

6,361,713

Merkle Root

b3ad9c948a48873753809a2baa8b2044955a26ca3e208dcbed9ca869797db931
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.

2.515 × 10⁹⁸(99-digit number)
25153581656818275983…69620110574717381119
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
2.515 × 10⁹⁸(99-digit number)
25153581656818275983…69620110574717381119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
5.030 × 10⁹⁸(99-digit number)
50307163313636551967…39240221149434762239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.006 × 10⁹⁹(100-digit number)
10061432662727310393…78480442298869524479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
2.012 × 10⁹⁹(100-digit number)
20122865325454620787…56960884597739048959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
4.024 × 10⁹⁹(100-digit number)
40245730650909241574…13921769195478097919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
8.049 × 10⁹⁹(100-digit number)
80491461301818483148…27843538390956195839
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.609 × 10¹⁰⁰(101-digit number)
16098292260363696629…55687076781912391679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
3.219 × 10¹⁰⁰(101-digit number)
32196584520727393259…11374153563824783359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
6.439 × 10¹⁰⁰(101-digit number)
64393169041454786518…22748307127649566719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.287 × 10¹⁰¹(102-digit number)
12878633808290957303…45496614255299133439
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:57,691,835 XPM·at block #6,805,969 · updates every 60s
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