Block #568,902

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 5/30/2014, 6:57:58 PM · Difficulty 10.9646 · 6,247,511 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
c10540b4e548bc90d8582ee0d0a9bce18fe6ea22d0c4538618e7355d625b0d78

Height

#568,902

Difficulty

10.964589

Transactions

2

Size

4.61 KB

Version

2

Bits

0af6ef4d

Nonce

135,756,793

Timestamp

5/30/2014, 6:57:58 PM

Confirmations

6,247,511

Merkle Root

8ffa817e8f223678852a11253a549731a3553d6d0e844515aa14eba47df58271
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.

1.190 × 10⁹⁹(100-digit number)
11907118754254077343…09409794005827479041
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
1.190 × 10⁹⁹(100-digit number)
11907118754254077343…09409794005827479041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
2.381 × 10⁹⁹(100-digit number)
23814237508508154686…18819588011654958081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
4.762 × 10⁹⁹(100-digit number)
47628475017016309372…37639176023309916161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
9.525 × 10⁹⁹(100-digit number)
95256950034032618745…75278352046619832321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.905 × 10¹⁰⁰(101-digit number)
19051390006806523749…50556704093239664641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
3.810 × 10¹⁰⁰(101-digit number)
38102780013613047498…01113408186479329281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
7.620 × 10¹⁰⁰(101-digit number)
76205560027226094996…02226816372958658561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.524 × 10¹⁰¹(102-digit number)
15241112005445218999…04453632745917317121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
3.048 × 10¹⁰¹(102-digit number)
30482224010890437998…08907265491834634241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
6.096 × 10¹⁰¹(102-digit number)
60964448021780875997…17814530983669268481
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:57,775,430 XPM·at block #6,816,412 · updates every 60s
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