Block #464,580

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 3/28/2014, 9:15:45 PM · Difficulty 10.4221 · 6,331,012 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
a8f3bf31898cd3ece9a0bd5fe1c5a6608e564c3051a19fc4cf8b37a21717c3dd

Height

#464,580

Difficulty

10.422064

Transactions

3

Size

1.92 KB

Version

2

Bits

0a6c0c64

Nonce

24,932

Timestamp

3/28/2014, 9:15:45 PM

Confirmations

6,331,012

Merkle Root

e8b8d631d7ae4b51151bcae8eb00540320f4b7f20f18552cc24e4ed772ec9440
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.

1.371 × 10⁹⁸(99-digit number)
13712064914662803548…50395238284019251039
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
1.371 × 10⁹⁸(99-digit number)
13712064914662803548…50395238284019251039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
2.742 × 10⁹⁸(99-digit number)
27424129829325607097…00790476568038502079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
5.484 × 10⁹⁸(99-digit number)
54848259658651214195…01580953136077004159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.096 × 10⁹⁹(100-digit number)
10969651931730242839…03161906272154008319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
2.193 × 10⁹⁹(100-digit number)
21939303863460485678…06323812544308016639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
4.387 × 10⁹⁹(100-digit number)
43878607726920971356…12647625088616033279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
8.775 × 10⁹⁹(100-digit number)
87757215453841942712…25295250177232066559
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.755 × 10¹⁰⁰(101-digit number)
17551443090768388542…50590500354464133119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
3.510 × 10¹⁰⁰(101-digit number)
35102886181536777085…01181000708928266239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
7.020 × 10¹⁰⁰(101-digit number)
70205772363073554170…02362001417856532479
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:57,608,799 XPM·at block #6,795,591 · 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.