Block #784,294

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 10/26/2014, 7:06:23 PM · Difficulty 10.9751 · 6,009,846 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
288785ee93d673f6c7f83e2f5f7ca4208ebccbe59be667bc224e406d5c4531b8

Height

#784,294

Difficulty

10.975107

Transactions

4

Size

13.94 KB

Version

2

Bits

0af9a0a5

Nonce

29,842,887

Timestamp

10/26/2014, 7:06:23 PM

Confirmations

6,009,846

Merkle Root

735a5e46742e61d1f25a2578cb117479d0cd126f61d2849a71193063feefd72c
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.

4.240 × 10⁹⁷(98-digit number)
42402650332591446179…12198652601564344319
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
4.240 × 10⁹⁷(98-digit number)
42402650332591446179…12198652601564344319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
8.480 × 10⁹⁷(98-digit number)
84805300665182892358…24397305203128688639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.696 × 10⁹⁸(99-digit number)
16961060133036578471…48794610406257377279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
3.392 × 10⁹⁸(99-digit number)
33922120266073156943…97589220812514754559
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
6.784 × 10⁹⁸(99-digit number)
67844240532146313887…95178441625029509119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.356 × 10⁹⁹(100-digit number)
13568848106429262777…90356883250059018239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
2.713 × 10⁹⁹(100-digit number)
27137696212858525554…80713766500118036479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
5.427 × 10⁹⁹(100-digit number)
54275392425717051109…61427533000236072959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.085 × 10¹⁰⁰(101-digit number)
10855078485143410221…22855066000472145919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
2.171 × 10¹⁰⁰(101-digit number)
21710156970286820443…45710132000944291839
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:57,597,147 XPM·at block #6,794,139 · updates every 60s
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