Block #330,892

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 12/26/2013, 11:56:41 PM · Difficulty 10.1687 · 6,465,294 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
c9b6e928842efccaf8697ea68b5994301190f891471fd5f5598f07e6cfa4aa19

Height

#330,892

Difficulty

10.168745

Transactions

7

Size

1.66 KB

Version

2

Bits

0a2b32d9

Nonce

29,944

Timestamp

12/26/2013, 11:56:41 PM

Confirmations

6,465,294

Merkle Root

8713d6949a88640e89397d4b30b9c3b0fd9f74e03e5498152a7bcc3384a33c10
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.

8.631 × 10¹⁰¹(102-digit number)
86312602711894227209…47966340122840496641
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
8.631 × 10¹⁰¹(102-digit number)
86312602711894227209…47966340122840496641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.726 × 10¹⁰²(103-digit number)
17262520542378845441…95932680245680993281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
3.452 × 10¹⁰²(103-digit number)
34525041084757690883…91865360491361986561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
6.905 × 10¹⁰²(103-digit number)
69050082169515381767…83730720982723973121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.381 × 10¹⁰³(104-digit number)
13810016433903076353…67461441965447946241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
2.762 × 10¹⁰³(104-digit number)
27620032867806152707…34922883930895892481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
5.524 × 10¹⁰³(104-digit number)
55240065735612305414…69845767861791784961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.104 × 10¹⁰⁴(105-digit number)
11048013147122461082…39691535723583569921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
2.209 × 10¹⁰⁴(105-digit number)
22096026294244922165…79383071447167139841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
4.419 × 10¹⁰⁴(105-digit number)
44192052588489844331…58766142894334279681
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:57,613,486 XPM·at block #6,796,185 · updates every 60s
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