Block #792,819

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 11/1/2014, 10:17:40 PM · Difficulty 10.9739 · 6,006,705 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
49d1fcb3d33755f2e5b6f8000be4928a6ec34dc9f405b8470a136ec1eaa99761

Height

#792,819

Difficulty

10.973886

Transactions

14

Size

4.23 KB

Version

2

Bits

0af95092

Nonce

166,787,304

Timestamp

11/1/2014, 10:17:40 PM

Confirmations

6,006,705

Merkle Root

4d649a7f8ed06509e4db83c788f25eab255beefc5fec44867690e8faa602059b
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.

9.919 × 10⁹⁴(95-digit number)
99198714667308305478…47954469966565675081
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
9.919 × 10⁹⁴(95-digit number)
99198714667308305478…47954469966565675081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.983 × 10⁹⁵(96-digit number)
19839742933461661095…95908939933131350161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
3.967 × 10⁹⁵(96-digit number)
39679485866923322191…91817879866262700321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
7.935 × 10⁹⁵(96-digit number)
79358971733846644383…83635759732525400641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.587 × 10⁹⁶(97-digit number)
15871794346769328876…67271519465050801281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
3.174 × 10⁹⁶(97-digit number)
31743588693538657753…34543038930101602561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
6.348 × 10⁹⁶(97-digit number)
63487177387077315506…69086077860203205121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.269 × 10⁹⁷(98-digit number)
12697435477415463101…38172155720406410241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
2.539 × 10⁹⁷(98-digit number)
25394870954830926202…76344311440812820481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
5.078 × 10⁹⁷(98-digit number)
50789741909661852405…52688622881625640961
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 Second 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 2CC formula:

2CC: p₁ (first prime), p₂ = 2p₁ − 1, p₃ = 2p₂ − 1, …
Circulating Supply:57,640,241 XPM·at block #6,799,523 · updates every 60s
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