Block #782,912

1CCLength 11★★★☆☆

Cunningham Chain of the First Kind · Discovered 10/25/2014, 8:06:47 PM · Difficulty 10.9751 · 6,009,508 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
1d72bedb1ee5a087821aea22247c79f1f50e92607dc913d2e4934d81aa2eb515

Height

#782,912

Difficulty

10.975052

Transactions

2

Size

13.74 KB

Version

2

Bits

0af99cfb

Nonce

54,370,359

Timestamp

10/25/2014, 8:06:47 PM

Confirmations

6,009,508

Merkle Root

6c61e88bbc6740aab6b9b778c75d5aec896603d4a447fbc19e68c1843a760ecd
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.

3.123 × 10⁹⁵(96-digit number)
31234537993302910996…85558971920652493599
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
3.123 × 10⁹⁵(96-digit number)
31234537993302910996…85558971920652493599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
6.246 × 10⁹⁵(96-digit number)
62469075986605821992…71117943841304987199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.249 × 10⁹⁶(97-digit number)
12493815197321164398…42235887682609974399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
2.498 × 10⁹⁶(97-digit number)
24987630394642328797…84471775365219948799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
4.997 × 10⁹⁶(97-digit number)
49975260789284657594…68943550730439897599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
9.995 × 10⁹⁶(97-digit number)
99950521578569315188…37887101460879795199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.999 × 10⁹⁷(98-digit number)
19990104315713863037…75774202921759590399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
3.998 × 10⁹⁷(98-digit number)
39980208631427726075…51548405843519180799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
7.996 × 10⁹⁷(98-digit number)
79960417262855452150…03096811687038361599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.599 × 10⁹⁸(99-digit number)
15992083452571090430…06193623374076723199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
11
2^10 × origin − 1
3.198 × 10⁹⁸(99-digit number)
31984166905142180860…12387246748153446399
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 11 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
RareChain length 11

Approximately 1 in 1,000 blocks. Noteworthy discoveries.

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:57,583,323 XPM·at block #6,792,419 · updates every 60s
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