Block #241,211

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 11/3/2013, 1:53:23 AM · Difficulty 9.9577 · 6,575,592 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
f6a327779f346b0eab2a90f11986aa6607b2e435fb6a8d14a896896de90f2beb

Height

#241,211

Difficulty

9.957722

Transactions

8

Size

2.00 KB

Version

2

Bits

09f52d3f

Nonce

10,846

Timestamp

11/3/2013, 1:53:23 AM

Confirmations

6,575,592

Merkle Root

1cf9f45a8d48c5b7d10d795ac83bd4fe5d70a9541eedbd1026060082af6cd5e1
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.

6.675 × 10¹⁰⁰(101-digit number)
66755934298365521897…71215212387754264319
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
6.675 × 10¹⁰⁰(101-digit number)
66755934298365521897…71215212387754264319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.335 × 10¹⁰¹(102-digit number)
13351186859673104379…42430424775508528639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
2.670 × 10¹⁰¹(102-digit number)
26702373719346208759…84860849551017057279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
5.340 × 10¹⁰¹(102-digit number)
53404747438692417518…69721699102034114559
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.068 × 10¹⁰²(103-digit number)
10680949487738483503…39443398204068229119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
2.136 × 10¹⁰²(103-digit number)
21361898975476967007…78886796408136458239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
4.272 × 10¹⁰²(103-digit number)
42723797950953934014…57773592816272916479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
8.544 × 10¹⁰²(103-digit number)
85447595901907868029…15547185632545832959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.708 × 10¹⁰³(104-digit number)
17089519180381573605…31094371265091665919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
3.417 × 10¹⁰³(104-digit number)
34179038360763147211…62188742530183331839
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 First 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 1CC formula:

1CC: p₁ (first prime), p₂ = 2p₁ + 1, p₃ = 2p₂ + 1, …
Circulating Supply:57,778,460 XPM·at block #6,816,802 · updates every 60s
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