Block #457,988

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 3/24/2014, 7:04:14 AM · Difficulty 10.4198 · 6,344,804 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
ce0ced9ae5fe5b422d27e21bb107d037cbfd655e4dfc22c321689931c158c234

Height

#457,988

Difficulty

10.419752

Transactions

6

Size

23.56 KB

Version

2

Bits

0a6b74e0

Nonce

21,480

Timestamp

3/24/2014, 7:04:14 AM

Confirmations

6,344,804

Merkle Root

ae7b820e7a6695999b916599dba70cc67c46a1ae40a4b892977ae996e1476972
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.

3.973 × 10⁹⁷(98-digit number)
39738675989138407514…93563914528909414161
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
3.973 × 10⁹⁷(98-digit number)
39738675989138407514…93563914528909414161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
7.947 × 10⁹⁷(98-digit number)
79477351978276815029…87127829057818828321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.589 × 10⁹⁸(99-digit number)
15895470395655363005…74255658115637656641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
3.179 × 10⁹⁸(99-digit number)
31790940791310726011…48511316231275313281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
6.358 × 10⁹⁸(99-digit number)
63581881582621452023…97022632462550626561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.271 × 10⁹⁹(100-digit number)
12716376316524290404…94045264925101253121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
2.543 × 10⁹⁹(100-digit number)
25432752633048580809…88090529850202506241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
5.086 × 10⁹⁹(100-digit number)
50865505266097161619…76181059700405012481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.017 × 10¹⁰⁰(101-digit number)
10173101053219432323…52362119400810024961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
2.034 × 10¹⁰⁰(101-digit number)
20346202106438864647…04724238801620049921
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 Second 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 2CC formula:

2CC: p₁ (first prime), p₂ = 2p₁ − 1, p₃ = 2p₂ − 1, …
Circulating Supply:57,666,362 XPM·at block #6,802,791 · updates every 60s
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