Block #327,247

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 12/24/2013, 10:10:18 AM · Difficulty 10.1774 · 6,465,416 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
835e71858cfd4c91828a7522d5ed947b57d531afe3fa46f18d77c94484c9f1fa

Height

#327,247

Difficulty

10.177380

Transactions

16

Size

4.20 KB

Version

2

Bits

0a2d68bf

Nonce

51,962

Timestamp

12/24/2013, 10:10:18 AM

Confirmations

6,465,416

Merkle Root

f16810c7a08f87ea764a528b5c0d6f40da4c8c8591dc862b4589d6aad58af05e
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.

1.414 × 10¹⁰⁷(108-digit number)
14143178203735141368…94464668923404179199
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
1.414 × 10¹⁰⁷(108-digit number)
14143178203735141368…94464668923404179199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
2.828 × 10¹⁰⁷(108-digit number)
28286356407470282736…88929337846808358399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
5.657 × 10¹⁰⁷(108-digit number)
56572712814940565472…77858675693616716799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.131 × 10¹⁰⁸(109-digit number)
11314542562988113094…55717351387233433599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
2.262 × 10¹⁰⁸(109-digit number)
22629085125976226189…11434702774466867199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
4.525 × 10¹⁰⁸(109-digit number)
45258170251952452378…22869405548933734399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
9.051 × 10¹⁰⁸(109-digit number)
90516340503904904756…45738811097867468799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.810 × 10¹⁰⁹(110-digit number)
18103268100780980951…91477622195734937599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
3.620 × 10¹⁰⁹(110-digit number)
36206536201561961902…82955244391469875199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
7.241 × 10¹⁰⁹(110-digit number)
72413072403123923805…65910488782939750399
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:57,585,274 XPM·at block #6,792,662 · updates every 60s
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