Block #455,045

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 3/22/2014, 8:16:17 AM · Difficulty 10.4023 · 6,335,945 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
c4632daf9d62c78f8a7afd9c2b0d93ac893028543368e9bf273a334cce96cb45

Height

#455,045

Difficulty

10.402290

Transactions

4

Size

22.30 KB

Version

2

Bits

0a66fc7d

Nonce

46,218

Timestamp

3/22/2014, 8:16:17 AM

Confirmations

6,335,945

Merkle Root

2494f748f6693bd57c3c1b070758d0368cb16ff5fdd4ef5e9ab5814473f96213
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.

6.707 × 10⁹⁸(99-digit number)
67070802183786615939…12181364210246479361
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
6.707 × 10⁹⁸(99-digit number)
67070802183786615939…12181364210246479361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.341 × 10⁹⁹(100-digit number)
13414160436757323187…24362728420492958721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
2.682 × 10⁹⁹(100-digit number)
26828320873514646375…48725456840985917441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
5.365 × 10⁹⁹(100-digit number)
53656641747029292751…97450913681971834881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.073 × 10¹⁰⁰(101-digit number)
10731328349405858550…94901827363943669761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
2.146 × 10¹⁰⁰(101-digit number)
21462656698811717100…89803654727887339521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
4.292 × 10¹⁰⁰(101-digit number)
42925313397623434201…79607309455774679041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
8.585 × 10¹⁰⁰(101-digit number)
85850626795246868402…59214618911549358081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.717 × 10¹⁰¹(102-digit number)
17170125359049373680…18429237823098716161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
3.434 × 10¹⁰¹(102-digit number)
34340250718098747360…36858475646197432321
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:57,571,934 XPM·at block #6,790,989 · updates every 60s