Block #911,590

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 1/27/2015, 5:30:49 AM · Difficulty 10.9309 · 5,895,337 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
b7372f997e3ffffd3010833b2a21acc9430712740da054a5f561590e8031d1e1

Height

#911,590

Difficulty

10.930888

Transactions

17

Size

3.99 KB

Version

2

Bits

0aee4eac

Nonce

860,261,067

Timestamp

1/27/2015, 5:30:49 AM

Confirmations

5,895,337

Merkle Root

de126546f64c463901e26f8e02356f5d773bf588b4b3647c4f1bbe394ec6caad
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.

6.020 × 10⁹⁶(97-digit number)
60209208272880141448…05408608807281820159
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
6.020 × 10⁹⁶(97-digit number)
60209208272880141448…05408608807281820159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.204 × 10⁹⁷(98-digit number)
12041841654576028289…10817217614563640319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
2.408 × 10⁹⁷(98-digit number)
24083683309152056579…21634435229127280639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
4.816 × 10⁹⁷(98-digit number)
48167366618304113158…43268870458254561279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
9.633 × 10⁹⁷(98-digit number)
96334733236608226317…86537740916509122559
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.926 × 10⁹⁸(99-digit number)
19266946647321645263…73075481833018245119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
3.853 × 10⁹⁸(99-digit number)
38533893294643290526…46150963666036490239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
7.706 × 10⁹⁸(99-digit number)
77067786589286581053…92301927332072980479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.541 × 10⁹⁹(100-digit number)
15413557317857316210…84603854664145960959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
3.082 × 10⁹⁹(100-digit number)
30827114635714632421…69207709328291921919
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:57,699,520 XPM·at block #6,806,926 · updates every 60s
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