Block #301,277

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 12/9/2013, 2:40:53 AM · Difficulty 9.9925 · 6,504,896 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
07e798e43ac225e23ca2d14e3f2718bc754c07db2bcc9e98e51ee9042b67b2af

Height

#301,277

Difficulty

9.992476

Transactions

18

Size

6.23 KB

Version

2

Bits

09fe12e5

Nonce

53,966

Timestamp

12/9/2013, 2:40:53 AM

Confirmations

6,504,896

Merkle Root

d4a6860665770bd4ed9731e9ff0869c692de52f3a7780edd82979d5a51172893
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.

9.294 × 10⁹¹(92-digit number)
92941745798414443148…45927161377123786839
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
9.294 × 10⁹¹(92-digit number)
92941745798414443148…45927161377123786839
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.858 × 10⁹²(93-digit number)
18588349159682888629…91854322754247573679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
3.717 × 10⁹²(93-digit number)
37176698319365777259…83708645508495147359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
7.435 × 10⁹²(93-digit number)
74353396638731554518…67417291016990294719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.487 × 10⁹³(94-digit number)
14870679327746310903…34834582033980589439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
2.974 × 10⁹³(94-digit number)
29741358655492621807…69669164067961178879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
5.948 × 10⁹³(94-digit number)
59482717310985243614…39338328135922357759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.189 × 10⁹⁴(95-digit number)
11896543462197048722…78676656271844715519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
2.379 × 10⁹⁴(95-digit number)
23793086924394097445…57353312543689431039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
4.758 × 10⁹⁴(95-digit number)
47586173848788194891…14706625087378862079
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:57,693,467 XPM·at block #6,806,172 · updates every 60s
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