Block #371,496

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 1/22/2014, 9:47:22 PM · Difficulty 10.4354 · 6,438,123 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
c37cadcd4527b1050dac9a827c3818f65b42fed5f5aacb6ce6f231eba3bf570d

Height

#371,496

Difficulty

10.435424

Transactions

6

Size

2.89 KB

Version

2

Bits

0a6f77ef

Nonce

2,088

Timestamp

1/22/2014, 9:47:22 PM

Confirmations

6,438,123

Merkle Root

a3680d213718f53f9f2d0423295f6794b83cbecc014294209112d431f9782e5a
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.

7.643 × 10⁹⁷(98-digit number)
76435954922220450951…84596335415179517839
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
7.643 × 10⁹⁷(98-digit number)
76435954922220450951…84596335415179517839
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.528 × 10⁹⁸(99-digit number)
15287190984444090190…69192670830359035679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
3.057 × 10⁹⁸(99-digit number)
30574381968888180380…38385341660718071359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
6.114 × 10⁹⁸(99-digit number)
61148763937776360761…76770683321436142719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.222 × 10⁹⁹(100-digit number)
12229752787555272152…53541366642872285439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
2.445 × 10⁹⁹(100-digit number)
24459505575110544304…07082733285744570879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
4.891 × 10⁹⁹(100-digit number)
48919011150221088608…14165466571489141759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
9.783 × 10⁹⁹(100-digit number)
97838022300442177217…28330933142978283519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.956 × 10¹⁰⁰(101-digit number)
19567604460088435443…56661866285956567039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
3.913 × 10¹⁰⁰(101-digit number)
39135208920176870887…13323732571913134079
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:57,721,029 XPM·at block #6,809,618 · updates every 60s
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