Block #322,461

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 12/21/2013, 12:40:29 AM · Difficulty 10.1932 · 6,471,998 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
4e8e1ad596a61098ededf7082be42b7aa8d7a3ec1d34dc43ee45df5bd8452860

Height

#322,461

Difficulty

10.193223

Transactions

6

Size

33.69 KB

Version

2

Bits

0a317709

Nonce

16,015

Timestamp

12/21/2013, 12:40:29 AM

Confirmations

6,471,998

Merkle Root

92f49d23c8b781f7ab591d292373a430b653b8a95c1942290f509d1e53af6610
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.

4.111 × 10⁹⁶(97-digit number)
41111051563452292267…94105313873203694939
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
4.111 × 10⁹⁶(97-digit number)
41111051563452292267…94105313873203694939
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
8.222 × 10⁹⁶(97-digit number)
82222103126904584535…88210627746407389879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.644 × 10⁹⁷(98-digit number)
16444420625380916907…76421255492814779759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
3.288 × 10⁹⁷(98-digit number)
32888841250761833814…52842510985629559519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
6.577 × 10⁹⁷(98-digit number)
65777682501523667628…05685021971259119039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.315 × 10⁹⁸(99-digit number)
13155536500304733525…11370043942518238079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
2.631 × 10⁹⁸(99-digit number)
26311073000609467051…22740087885036476159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
5.262 × 10⁹⁸(99-digit number)
52622146001218934102…45480175770072952319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.052 × 10⁹⁹(100-digit number)
10524429200243786820…90960351540145904639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
2.104 × 10⁹⁹(100-digit number)
21048858400487573640…81920703080291809279
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:57,599,713 XPM·at block #6,794,458 · updates every 60s
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