Block #895,483

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 1/14/2015, 11:45:26 PM · Difficulty 10.9484 · 5,908,586 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
fcf3cd2bf378666ed6db050da28bdc5ad59f9af4477cb1b1a1dfe0a7a1aee61b

Height

#895,483

Difficulty

10.948421

Transactions

10

Size

3.78 KB

Version

2

Bits

0af2cbbd

Nonce

940,075,484

Timestamp

1/14/2015, 11:45:26 PM

Confirmations

5,908,586

Merkle Root

49c6528fcd85307aa2cd16c9a10dac13c3a0d567fc44638dbe2c966a3bf90a0a
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.

2.473 × 10⁹⁸(99-digit number)
24739742286082003015…11944833882328432639
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
2.473 × 10⁹⁸(99-digit number)
24739742286082003015…11944833882328432639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
4.947 × 10⁹⁸(99-digit number)
49479484572164006031…23889667764656865279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
9.895 × 10⁹⁸(99-digit number)
98958969144328012062…47779335529313730559
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.979 × 10⁹⁹(100-digit number)
19791793828865602412…95558671058627461119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
3.958 × 10⁹⁹(100-digit number)
39583587657731204825…91117342117254922239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
7.916 × 10⁹⁹(100-digit number)
79167175315462409650…82234684234509844479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.583 × 10¹⁰⁰(101-digit number)
15833435063092481930…64469368469019688959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
3.166 × 10¹⁰⁰(101-digit number)
31666870126184963860…28938736938039377919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
6.333 × 10¹⁰⁰(101-digit number)
63333740252369927720…57877473876078755839
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.266 × 10¹⁰¹(102-digit number)
12666748050473985544…15754947752157511679
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:57,676,608 XPM·at block #6,804,068 · updates every 60s
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