Block #680,530

1CCLength 12★★★★☆

Cunningham Chain of the First Kind · Discovered 8/16/2014, 7:21:29 PM · Difficulty 10.9624 · 6,116,149 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
1eea683a09637dd2ad1b29e0bbed9a6e4d171117eab34a07c302519587403f77

Height

#680,530

Difficulty

10.962385

Transactions

8

Size

2.87 KB

Version

2

Bits

0af65ed5

Nonce

1,085,342,456

Timestamp

8/16/2014, 7:21:29 PM

Confirmations

6,116,149

Merkle Root

c729b55c033374aa283992c2cc6ff88e4bbcd1d4cf6530c2d690af6e0b78d077
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.

1.182 × 10⁹⁷(98-digit number)
11826289817049165713…48310248232909330549
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
1.182 × 10⁹⁷(98-digit number)
11826289817049165713…48310248232909330549
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
2.365 × 10⁹⁷(98-digit number)
23652579634098331427…96620496465818661099
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
4.730 × 10⁹⁷(98-digit number)
47305159268196662855…93240992931637322199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
9.461 × 10⁹⁷(98-digit number)
94610318536393325711…86481985863274644399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.892 × 10⁹⁸(99-digit number)
18922063707278665142…72963971726549288799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
3.784 × 10⁹⁸(99-digit number)
37844127414557330284…45927943453098577599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
7.568 × 10⁹⁸(99-digit number)
75688254829114660568…91855886906197155199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.513 × 10⁹⁹(100-digit number)
15137650965822932113…83711773812394310399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
3.027 × 10⁹⁹(100-digit number)
30275301931645864227…67423547624788620799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
6.055 × 10⁹⁹(100-digit number)
60550603863291728455…34847095249577241599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
11
2^10 × origin − 1
1.211 × 10¹⁰⁰(101-digit number)
12110120772658345691…69694190499154483199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
12
2^11 × origin − 1
2.422 × 10¹⁰⁰(101-digit number)
24220241545316691382…39388380998308966399
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 12 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
ExceptionalChain length 12

Around 1 in 10,000 blocks. A significant mathematical achievement.

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:57,617,437 XPM·at block #6,796,678 · updates every 60s
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