Block #2,246,438

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 8/11/2017, 6:28:52 AM · Difficulty 10.9476 · 4,587,301 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
2f68059101642ef7d8d4e7b9d3a684a8886d38653df37cde7bdf2e43668b24e2

Height

#2,246,438

Difficulty

10.947643

Transactions

4

Size

1023 B

Version

2

Bits

0af298b6

Nonce

1,490,588,489

Timestamp

8/11/2017, 6:28:52 AM

Confirmations

4,587,301

Merkle Root

26a9ac19b4e100b05ef1ea6a0d4edbdb5bedf05305821be2e9c4e513ad7d5be9
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.

2.523 × 10⁹⁴(95-digit number)
25231492276066833286…29784364290360834479
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
2.523 × 10⁹⁴(95-digit number)
25231492276066833286…29784364290360834479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
5.046 × 10⁹⁴(95-digit number)
50462984552133666573…59568728580721668959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.009 × 10⁹⁵(96-digit number)
10092596910426733314…19137457161443337919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
2.018 × 10⁹⁵(96-digit number)
20185193820853466629…38274914322886675839
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
4.037 × 10⁹⁵(96-digit number)
40370387641706933259…76549828645773351679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
8.074 × 10⁹⁵(96-digit number)
80740775283413866518…53099657291546703359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.614 × 10⁹⁶(97-digit number)
16148155056682773303…06199314583093406719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
3.229 × 10⁹⁶(97-digit number)
32296310113365546607…12398629166186813439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
6.459 × 10⁹⁶(97-digit number)
64592620226731093214…24797258332373626879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.291 × 10⁹⁷(98-digit number)
12918524045346218642…49594516664747253759
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:57,914,129 XPM·at block #6,833,738 · updates every 60s
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