Block #3,012,988

1CCLength 11★★★☆☆

Cunningham Chain of the First Kind · Discovered 1/17/2019, 5:23:45 AM · Difficulty 11.1735 · 3,802,861 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
0f872b79f16eb99660894fca3f3a1c254c12a51610a447b7627002df76ef7c0d

Height

#3,012,988

Difficulty

11.173516

Transactions

4

Size

1.33 KB

Version

2

Bits

0b2c6b93

Nonce

1,937,611,550

Timestamp

1/17/2019, 5:23:45 AM

Confirmations

3,802,861

Merkle Root

19a7e32152404d2cbfc7a25741e2cd62890527d4b3b50fece726c3f0842097e8
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.

1.507 × 10⁹⁷(98-digit number)
15077174112534150848…16397924768494796799
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
1.507 × 10⁹⁷(98-digit number)
15077174112534150848…16397924768494796799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
3.015 × 10⁹⁷(98-digit number)
30154348225068301696…32795849536989593599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
6.030 × 10⁹⁷(98-digit number)
60308696450136603392…65591699073979187199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.206 × 10⁹⁸(99-digit number)
12061739290027320678…31183398147958374399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
2.412 × 10⁹⁸(99-digit number)
24123478580054641357…62366796295916748799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
4.824 × 10⁹⁸(99-digit number)
48246957160109282714…24733592591833497599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
9.649 × 10⁹⁸(99-digit number)
96493914320218565428…49467185183666995199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.929 × 10⁹⁹(100-digit number)
19298782864043713085…98934370367333990399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
3.859 × 10⁹⁹(100-digit number)
38597565728087426171…97868740734667980799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
7.719 × 10⁹⁹(100-digit number)
77195131456174852342…95737481469335961599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
11
2^10 × origin − 1
1.543 × 10¹⁰⁰(101-digit number)
15439026291234970468…91474962938671923199
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:57,770,902 XPM·at block #6,815,848 · updates every 60s
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