Block #368,741

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 1/20/2014, 10:20:05 PM · Difficulty 10.4450 · 6,429,639 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
0e96cade30900f06dba1b0f28bfd56ff8b82beb598f34de09800933e4b79bd4f

Height

#368,741

Difficulty

10.444984

Transactions

5

Size

1.52 KB

Version

2

Bits

0a71ea79

Nonce

33,554,584

Timestamp

1/20/2014, 10:20:05 PM

Confirmations

6,429,639

Merkle Root

3eccd352ed8f4b250f7cb13c040c770ad0a2a0ad305c8799842e0ca1e0502d63
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.

2.390 × 10⁹⁵(96-digit number)
23902770186500250107…69180682129978034059
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
2.390 × 10⁹⁵(96-digit number)
23902770186500250107…69180682129978034059
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
4.780 × 10⁹⁵(96-digit number)
47805540373000500214…38361364259956068119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
9.561 × 10⁹⁵(96-digit number)
95611080746001000428…76722728519912136239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.912 × 10⁹⁶(97-digit number)
19122216149200200085…53445457039824272479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
3.824 × 10⁹⁶(97-digit number)
38244432298400400171…06890914079648544959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
7.648 × 10⁹⁶(97-digit number)
76488864596800800342…13781828159297089919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.529 × 10⁹⁷(98-digit number)
15297772919360160068…27563656318594179839
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
3.059 × 10⁹⁷(98-digit number)
30595545838720320137…55127312637188359679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
6.119 × 10⁹⁷(98-digit number)
61191091677440640274…10254625274376719359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.223 × 10⁹⁸(99-digit number)
12238218335488128054…20509250548753438719
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:57,631,046 XPM·at block #6,798,379 · updates every 60s
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