Block #507,453

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 4/23/2014, 6:10:05 PM · Difficulty 10.8163 · 6,310,515 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
c697533adeafc90e8b81b9305caec875071d9a6ecde5fd325f10fbd2baf103a5

Height

#507,453

Difficulty

10.816267

Transactions

7

Size

1.67 KB

Version

2

Bits

0ad0f6d8

Nonce

1,491

Timestamp

4/23/2014, 6:10:05 PM

Confirmations

6,310,515

Merkle Root

71f5f9275b005103e3e6003c91bf5e8ebc76df2e4ec9553b300b29323bc7905d
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.

7.428 × 10⁹⁹(100-digit number)
74280558458503474981…68171549080527769601
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
7.428 × 10⁹⁹(100-digit number)
74280558458503474981…68171549080527769601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.485 × 10¹⁰⁰(101-digit number)
14856111691700694996…36343098161055539201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
2.971 × 10¹⁰⁰(101-digit number)
29712223383401389992…72686196322111078401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
5.942 × 10¹⁰⁰(101-digit number)
59424446766802779985…45372392644222156801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.188 × 10¹⁰¹(102-digit number)
11884889353360555997…90744785288444313601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
2.376 × 10¹⁰¹(102-digit number)
23769778706721111994…81489570576888627201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
4.753 × 10¹⁰¹(102-digit number)
47539557413442223988…62979141153777254401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
9.507 × 10¹⁰¹(102-digit number)
95079114826884447976…25958282307554508801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.901 × 10¹⁰²(103-digit number)
19015822965376889595…51916564615109017601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
3.803 × 10¹⁰²(103-digit number)
38031645930753779190…03833129230218035201
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:57,787,814 XPM·at block #6,817,967 · updates every 60s
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