Block #496,847

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 4/17/2014, 7:23:12 AM · Difficulty 10.7595 · 6,298,073 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
a5a3bb6c99efaa469338329ade6e3e5ef6772509cfa32805acc401ffd86d7edb

Height

#496,847

Difficulty

10.759517

Transactions

8

Size

2.30 KB

Version

2

Bits

0ac26fbb

Nonce

81,733

Timestamp

4/17/2014, 7:23:12 AM

Confirmations

6,298,073

Merkle Root

72b8ad0e7ecb734b2dae8f75854f304e441ce7a680a7dfe816f8d471f1e99dcc
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.

6.019 × 10⁹⁵(96-digit number)
60192120564767142154…98209611601022167679
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
6.019 × 10⁹⁵(96-digit number)
60192120564767142154…98209611601022167679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.203 × 10⁹⁶(97-digit number)
12038424112953428430…96419223202044335359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
2.407 × 10⁹⁶(97-digit number)
24076848225906856861…92838446404088670719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
4.815 × 10⁹⁶(97-digit number)
48153696451813713723…85676892808177341439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
9.630 × 10⁹⁶(97-digit number)
96307392903627427447…71353785616354682879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.926 × 10⁹⁷(98-digit number)
19261478580725485489…42707571232709365759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
3.852 × 10⁹⁷(98-digit number)
38522957161450970979…85415142465418731519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
7.704 × 10⁹⁷(98-digit number)
77045914322901941958…70830284930837463039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.540 × 10⁹⁸(99-digit number)
15409182864580388391…41660569861674926079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
3.081 × 10⁹⁸(99-digit number)
30818365729160776783…83321139723349852159
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:57,603,391 XPM·at block #6,794,919 · updates every 60s
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