Block #323,252

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 12/21/2013, 12:55:47 PM · Difficulty 10.2029 · 6,473,062 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
c41c7f203d4f1b686d518dbf922b9026799860fdcde8e79422a7a8c34370ab73

Height

#323,252

Difficulty

10.202897

Transactions

18

Size

5.39 KB

Version

2

Bits

0a33f10f

Nonce

10,169

Timestamp

12/21/2013, 12:55:47 PM

Confirmations

6,473,062

Merkle Root

a570830615b801b1b6277250c842eb01b63a4d728e772604eefde9e252250ad1
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.

2.028 × 10⁹⁴(95-digit number)
20285317584724709267…52214365324583551999
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
2.028 × 10⁹⁴(95-digit number)
20285317584724709267…52214365324583551999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
4.057 × 10⁹⁴(95-digit number)
40570635169449418535…04428730649167103999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
8.114 × 10⁹⁴(95-digit number)
81141270338898837070…08857461298334207999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.622 × 10⁹⁵(96-digit number)
16228254067779767414…17714922596668415999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
3.245 × 10⁹⁵(96-digit number)
32456508135559534828…35429845193336831999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
6.491 × 10⁹⁵(96-digit number)
64913016271119069656…70859690386673663999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.298 × 10⁹⁶(97-digit number)
12982603254223813931…41719380773347327999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
2.596 × 10⁹⁶(97-digit number)
25965206508447627862…83438761546694655999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
5.193 × 10⁹⁶(97-digit number)
51930413016895255725…66877523093389311999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.038 × 10⁹⁷(98-digit number)
10386082603379051145…33755046186778623999
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:57,614,500 XPM·at block #6,796,313 · updates every 60s
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