Block #539,337

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 5/12/2014, 4:35:08 PM · Difficulty 10.9274 · 6,266,023 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
63388edfcaaa509c02c48dd70d63aefae1755053a403127fed360e832a4bbe0b

Height

#539,337

Difficulty

10.927350

Transactions

2

Size

616 B

Version

2

Bits

0aed66d1

Nonce

24,103,304

Timestamp

5/12/2014, 4:35:08 PM

Confirmations

6,266,023

Merkle Root

b45e33e4bdc2e024c1d1e955886b81fb1095a243f8c0cfc910c849d01622626d
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.

6.743 × 10⁹⁹(100-digit number)
67436582508166262394…12278945904678169601
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
6.743 × 10⁹⁹(100-digit number)
67436582508166262394…12278945904678169601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.348 × 10¹⁰⁰(101-digit number)
13487316501633252478…24557891809356339201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
2.697 × 10¹⁰⁰(101-digit number)
26974633003266504957…49115783618712678401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
5.394 × 10¹⁰⁰(101-digit number)
53949266006533009915…98231567237425356801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.078 × 10¹⁰¹(102-digit number)
10789853201306601983…96463134474850713601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
2.157 × 10¹⁰¹(102-digit number)
21579706402613203966…92926268949701427201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
4.315 × 10¹⁰¹(102-digit number)
43159412805226407932…85852537899402854401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
8.631 × 10¹⁰¹(102-digit number)
86318825610452815865…71705075798805708801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.726 × 10¹⁰²(103-digit number)
17263765122090563173…43410151597611417601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
3.452 × 10¹⁰²(103-digit number)
34527530244181126346…86820303195222835201
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:57,686,953 XPM·at block #6,805,359 · 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.