Block #283,079

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 11/29/2013, 2:53:15 PM · Difficulty 9.9804 · 6,522,768 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
182cf05caeeb5cf1622408176eedf92cc7118778368a26df316b3d293c8c1416

Height

#283,079

Difficulty

9.980413

Transactions

14

Size

4.69 KB

Version

2

Bits

09fafc5d

Nonce

2,342

Timestamp

11/29/2013, 2:53:15 PM

Confirmations

6,522,768

Merkle Root

fc90d56e100e72be868bfed65fb05426ab8c59079910d4efe0150734974222f0
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.

1.422 × 10¹⁰²(103-digit number)
14229477715711306406…83860396613591172801
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
1.422 × 10¹⁰²(103-digit number)
14229477715711306406…83860396613591172801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
2.845 × 10¹⁰²(103-digit number)
28458955431422612812…67720793227182345601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
5.691 × 10¹⁰²(103-digit number)
56917910862845225625…35441586454364691201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.138 × 10¹⁰³(104-digit number)
11383582172569045125…70883172908729382401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
2.276 × 10¹⁰³(104-digit number)
22767164345138090250…41766345817458764801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
4.553 × 10¹⁰³(104-digit number)
45534328690276180500…83532691634917529601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
9.106 × 10¹⁰³(104-digit number)
91068657380552361001…67065383269835059201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.821 × 10¹⁰⁴(105-digit number)
18213731476110472200…34130766539670118401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
3.642 × 10¹⁰⁴(105-digit number)
36427462952220944400…68261533079340236801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
7.285 × 10¹⁰⁴(105-digit number)
72854925904441888800…36523066158680473601
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:57,690,856 XPM·at block #6,805,846 · updates every 60s
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