Block #602,758

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 6/26/2014, 12:59:40 PM · Difficulty 10.9129 · 6,199,373 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
d591a73bad6f5b3ec91a213591ef86ee56a35bc28ae4543d1077d5c14802a902

Height

#602,758

Difficulty

10.912883

Transactions

3

Size

808 B

Version

2

Bits

0ae9b2b6

Nonce

20,633

Timestamp

6/26/2014, 12:59:40 PM

Confirmations

6,199,373

Merkle Root

03174cf99046ad47e6941846d5afd2e0309bf09c5bbd3cf46782fe7f971f74d1
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.

1.782 × 10¹⁰¹(102-digit number)
17821081518340105292…50683300516204740801
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
1.782 × 10¹⁰¹(102-digit number)
17821081518340105292…50683300516204740801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
3.564 × 10¹⁰¹(102-digit number)
35642163036680210585…01366601032409481601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
7.128 × 10¹⁰¹(102-digit number)
71284326073360421170…02733202064818963201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.425 × 10¹⁰²(103-digit number)
14256865214672084234…05466404129637926401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
2.851 × 10¹⁰²(103-digit number)
28513730429344168468…10932808259275852801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
5.702 × 10¹⁰²(103-digit number)
57027460858688336936…21865616518551705601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
1.140 × 10¹⁰³(104-digit number)
11405492171737667387…43731233037103411201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
2.281 × 10¹⁰³(104-digit number)
22810984343475334774…87462466074206822401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
4.562 × 10¹⁰³(104-digit number)
45621968686950669548…74924932148413644801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
9.124 × 10¹⁰³(104-digit number)
91243937373901339097…49849864296827289601
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:57,661,053 XPM·at block #6,802,130 · updates every 60s
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