Block #283,292

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 11/29/2013, 4:35:41 PM · Difficulty 9.9808 · 6,512,089 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
6492012ef6376c1ff27ebf6bb366f16e3b4f795dbe6a9a8d4c217ce2882f1dcb

Height

#283,292

Difficulty

9.980847

Transactions

16

Size

4.47 KB

Version

2

Bits

09fb18d0

Nonce

14,667

Timestamp

11/29/2013, 4:35:41 PM

Confirmations

6,512,089

Merkle Root

c22867730d06509b494b2dd29b2d20af43ca5a7ec1d4fa5447aa9b904e70eba4
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.

8.364 × 10¹⁰⁰(101-digit number)
83640502856210791739…08792880072508696001
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
8.364 × 10¹⁰⁰(101-digit number)
83640502856210791739…08792880072508696001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.672 × 10¹⁰¹(102-digit number)
16728100571242158347…17585760145017392001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
3.345 × 10¹⁰¹(102-digit number)
33456201142484316695…35171520290034784001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
6.691 × 10¹⁰¹(102-digit number)
66912402284968633391…70343040580069568001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.338 × 10¹⁰²(103-digit number)
13382480456993726678…40686081160139136001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
2.676 × 10¹⁰²(103-digit number)
26764960913987453356…81372162320278272001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
5.352 × 10¹⁰²(103-digit number)
53529921827974906713…62744324640556544001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.070 × 10¹⁰³(104-digit number)
10705984365594981342…25488649281113088001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
2.141 × 10¹⁰³(104-digit number)
21411968731189962685…50977298562226176001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
4.282 × 10¹⁰³(104-digit number)
42823937462379925370…01954597124452352001
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:57,607,106 XPM·at block #6,795,380 · updates every 60s
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