Block #322,778

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 12/21/2013, 6:18:53 AM · Difficulty 10.1904 · 6,488,059 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
1ea31a14ead51818ad73f512e3f4adfd7b154e089832d49f200b1d1713e8645f

Height

#322,778

Difficulty

10.190384

Transactions

27

Size

7.95 KB

Version

2

Bits

0a30bd07

Nonce

823,857

Timestamp

12/21/2013, 6:18:53 AM

Confirmations

6,488,059

Merkle Root

388111f7dc5c3e63c38f227f08be1f7ff7bb95ad804b63fc8d3d50fa802ef931
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.

1.147 × 10¹⁰⁰(101-digit number)
11474465787826572354…32398988754339310369
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
1.147 × 10¹⁰⁰(101-digit number)
11474465787826572354…32398988754339310369
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
2.294 × 10¹⁰⁰(101-digit number)
22948931575653144709…64797977508678620739
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
4.589 × 10¹⁰⁰(101-digit number)
45897863151306289418…29595955017357241479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
9.179 × 10¹⁰⁰(101-digit number)
91795726302612578836…59191910034714482959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.835 × 10¹⁰¹(102-digit number)
18359145260522515767…18383820069428965919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
3.671 × 10¹⁰¹(102-digit number)
36718290521045031534…36767640138857931839
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
7.343 × 10¹⁰¹(102-digit number)
73436581042090063069…73535280277715863679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.468 × 10¹⁰²(103-digit number)
14687316208418012613…47070560555431727359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
2.937 × 10¹⁰²(103-digit number)
29374632416836025227…94141121110863454719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
5.874 × 10¹⁰²(103-digit number)
58749264833672050455…88282242221726909439
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:57,730,792 XPM·at block #6,810,836 · updates every 60s
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