Block #52,924

2CCLength 8★☆☆☆☆

Cunningham Chain of the Second Kind · Discovered 7/16/2013, 12:48:05 PM · Difficulty 8.9178 · 6,752,163 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
994616b82e1a212e7812ef0897c0c183448379c9b6a4238b2b4e23b306ee0d97

Height

#52,924

Difficulty

8.917831

Transactions

3

Size

2.50 KB

Version

2

Bits

08eaf6fb

Nonce

11

Timestamp

7/16/2013, 12:48:05 PM

Confirmations

6,752,163

Merkle Root

558a17519f131a7f486e7dc8f7e0aed50a722fba3d7f976abd4e9cf78a00d5e2
Transactions (3)
1 in → 1 out12.5900 XPM110 B
3 in → 1 out13.2000 XPM455 B
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.

1.502 × 10⁹⁸(99-digit number)
15023014471666368468…41315185025206903041
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
1.502 × 10⁹⁸(99-digit number)
15023014471666368468…41315185025206903041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
3.004 × 10⁹⁸(99-digit number)
30046028943332736937…82630370050413806081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
6.009 × 10⁹⁸(99-digit number)
60092057886665473874…65260740100827612161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.201 × 10⁹⁹(100-digit number)
12018411577333094774…30521480201655224321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
2.403 × 10⁹⁹(100-digit number)
24036823154666189549…61042960403310448641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
4.807 × 10⁹⁹(100-digit number)
48073646309332379099…22085920806620897281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
9.614 × 10⁹⁹(100-digit number)
96147292618664758199…44171841613241794561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.922 × 10¹⁰⁰(101-digit number)
19229458523732951639…88343683226483589121
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 8 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
CommonChain length 8

Found in most blocks. The baseline for Primecoin's proof-of-work.

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:57,684,761 XPM·at block #6,805,086 · updates every 60s
xpmprime.info is a work in progress. If you enjoy using this service you can support this project with a Primecoin donation.