Block #441,040

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 3/12/2014, 8:24:40 PM · Difficulty 10.3529 · 6,361,491 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
1f3bedf5d89f33ffc4d814cd5781fc2982cc68ed00e818810d88373ebb60e80c

Height

#441,040

Difficulty

10.352927

Transactions

5

Size

1.09 KB

Version

2

Bits

0a5a596f

Nonce

123,075

Timestamp

3/12/2014, 8:24:40 PM

Confirmations

6,361,491

Merkle Root

583bc510a5bab99db9b767ea39344330612dca6da1f15af29e5a7bc801cf67a7
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.

1.103 × 10¹⁰⁵(106-digit number)
11039328437376873217…12965451511548238401
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
1.103 × 10¹⁰⁵(106-digit number)
11039328437376873217…12965451511548238401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
2.207 × 10¹⁰⁵(106-digit number)
22078656874753746435…25930903023096476801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
4.415 × 10¹⁰⁵(106-digit number)
44157313749507492870…51861806046192953601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
8.831 × 10¹⁰⁵(106-digit number)
88314627499014985740…03723612092385907201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.766 × 10¹⁰⁶(107-digit number)
17662925499802997148…07447224184771814401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
3.532 × 10¹⁰⁶(107-digit number)
35325850999605994296…14894448369543628801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
7.065 × 10¹⁰⁶(107-digit number)
70651701999211988592…29788896739087257601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.413 × 10¹⁰⁷(108-digit number)
14130340399842397718…59577793478174515201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
2.826 × 10¹⁰⁷(108-digit number)
28260680799684795437…19155586956349030401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
5.652 × 10¹⁰⁷(108-digit number)
56521361599369590874…38311173912698060801
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:57,664,257 XPM·at block #6,802,530 · updates every 60s
xpmprime.info is a work in progress. If you enjoy using this service you can support this project with a Primecoin donation.