Block #323,804

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 12/21/2013, 9:37:10 PM · Difficulty 10.2077 · 6,472,205 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
dc79ca06e5bba2ecda8236a7141db569608addc774f556bcee2d08f9dc334fe9

Height

#323,804

Difficulty

10.207681

Transactions

11

Size

14.98 KB

Version

2

Bits

0a352a9a

Nonce

418,212

Timestamp

12/21/2013, 9:37:10 PM

Confirmations

6,472,205

Merkle Root

55d51079972fc77b6ffc02dd7a5a197fbffdb109adcdb74937b75e68722c4da8
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.

4.006 × 10⁹⁶(97-digit number)
40062196386188986713…87587794869974865049
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
4.006 × 10⁹⁶(97-digit number)
40062196386188986713…87587794869974865049
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
8.012 × 10⁹⁶(97-digit number)
80124392772377973427…75175589739949730099
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.602 × 10⁹⁷(98-digit number)
16024878554475594685…50351179479899460199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
3.204 × 10⁹⁷(98-digit number)
32049757108951189370…00702358959798920399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
6.409 × 10⁹⁷(98-digit number)
64099514217902378741…01404717919597840799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.281 × 10⁹⁸(99-digit number)
12819902843580475748…02809435839195681599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
2.563 × 10⁹⁸(99-digit number)
25639805687160951496…05618871678391363199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
5.127 × 10⁹⁸(99-digit number)
51279611374321902993…11237743356782726399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.025 × 10⁹⁹(100-digit number)
10255922274864380598…22475486713565452799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
2.051 × 10⁹⁹(100-digit number)
20511844549728761197…44950973427130905599
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:57,612,162 XPM·at block #6,796,008 · updates every 60s
xpmprime.info is a work in progress. If you enjoy using this service you can support this project with a Primecoin donation.