Block #560,570

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 5/24/2014, 9:46:00 PM · Difficulty 10.9653 · 6,237,027 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
17f74edfd00ca263529b39964492b6eef4ad6a9d304acf4ea6c5dfce52137497

Height

#560,570

Difficulty

10.965308

Transactions

15

Size

4.74 KB

Version

2

Bits

0af71e6c

Nonce

460,337,392

Timestamp

5/24/2014, 9:46:00 PM

Confirmations

6,237,027

Merkle Root

d91208e34f70f7f14cfac580b38e86efe74631f91faf11c473644f76a6d638b4
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.

9.779 × 10⁹⁸(99-digit number)
97796322791630799834…33570302223543439361
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
9.779 × 10⁹⁸(99-digit number)
97796322791630799834…33570302223543439361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.955 × 10⁹⁹(100-digit number)
19559264558326159966…67140604447086878721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
3.911 × 10⁹⁹(100-digit number)
39118529116652319933…34281208894173757441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
7.823 × 10⁹⁹(100-digit number)
78237058233304639867…68562417788347514881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.564 × 10¹⁰⁰(101-digit number)
15647411646660927973…37124835576695029761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
3.129 × 10¹⁰⁰(101-digit number)
31294823293321855947…74249671153390059521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
6.258 × 10¹⁰⁰(101-digit number)
62589646586643711894…48499342306780119041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.251 × 10¹⁰¹(102-digit number)
12517929317328742378…96998684613560238081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
2.503 × 10¹⁰¹(102-digit number)
25035858634657484757…93997369227120476161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
5.007 × 10¹⁰¹(102-digit number)
50071717269314969515…87994738454240952321
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:57,624,757 XPM·at block #6,797,596 · updates every 60s
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