Block #488,079

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 4/12/2014, 12:49:15 PM · Difficulty 10.6478 · 6,322,556 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
7611cf5da9c4cb6143a7869864921b3e66be5b9256c07a000ba72e011ab6f4b3

Height

#488,079

Difficulty

10.647797

Transactions

2

Size

583 B

Version

2

Bits

0aa5d5fe

Nonce

40,263

Timestamp

4/12/2014, 12:49:15 PM

Confirmations

6,322,556

Merkle Root

dca0b1a036e843a0999aaa7fd9c0824a15c914e364593958d8702f47be821218
Transactions (2)
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.

1.175 × 10¹⁰⁰(101-digit number)
11758784806883286356…15842587560814284801
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
1.175 × 10¹⁰⁰(101-digit number)
11758784806883286356…15842587560814284801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
2.351 × 10¹⁰⁰(101-digit number)
23517569613766572712…31685175121628569601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
4.703 × 10¹⁰⁰(101-digit number)
47035139227533145424…63370350243257139201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
9.407 × 10¹⁰⁰(101-digit number)
94070278455066290849…26740700486514278401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.881 × 10¹⁰¹(102-digit number)
18814055691013258169…53481400973028556801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
3.762 × 10¹⁰¹(102-digit number)
37628111382026516339…06962801946057113601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
7.525 × 10¹⁰¹(102-digit number)
75256222764053032679…13925603892114227201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.505 × 10¹⁰²(103-digit number)
15051244552810606535…27851207784228454401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
3.010 × 10¹⁰²(103-digit number)
30102489105621213071…55702415568456908801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
6.020 × 10¹⁰²(103-digit number)
60204978211242426143…11404831136913817601
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:57,729,167 XPM·at block #6,810,634 · updates every 60s
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