Block #2,669,570

1CCLength 11★★★☆☆

Cunningham Chain of the First Kind · Discovered 5/20/2018, 7:37:56 AM · Difficulty 11.6792 · 4,161,777 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
12081d816e54b5de219f00f49df7495c2b8a9f9983eb20db708b05e881af33b6

Height

#2,669,570

Difficulty

11.679181

Transactions

5

Size

1.33 KB

Version

2

Bits

0baddecc

Nonce

345,641,389

Timestamp

5/20/2018, 7:37:56 AM

Confirmations

4,161,777

Merkle Root

53cde91fed50283e5968adadc86499d15fbf7aba5cbf02b870ca80231ba68ed4
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.

6.278 × 10⁹⁴(95-digit number)
62783666212777456232…61922021993848104399
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
6.278 × 10⁹⁴(95-digit number)
62783666212777456232…61922021993848104399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.255 × 10⁹⁵(96-digit number)
12556733242555491246…23844043987696208799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
2.511 × 10⁹⁵(96-digit number)
25113466485110982492…47688087975392417599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
5.022 × 10⁹⁵(96-digit number)
50226932970221964985…95376175950784835199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.004 × 10⁹⁶(97-digit number)
10045386594044392997…90752351901569670399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
2.009 × 10⁹⁶(97-digit number)
20090773188088785994…81504703803139340799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
4.018 × 10⁹⁶(97-digit number)
40181546376177571988…63009407606278681599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
8.036 × 10⁹⁶(97-digit number)
80363092752355143977…26018815212557363199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.607 × 10⁹⁷(98-digit number)
16072618550471028795…52037630425114726399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
3.214 × 10⁹⁷(98-digit number)
32145237100942057590…04075260850229452799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
11
2^10 × origin − 1
6.429 × 10⁹⁷(98-digit number)
64290474201884115181…08150521700458905599
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:57,894,931 XPM·at block #6,831,346 · updates every 60s
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