Block #435,067

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 3/8/2014, 4:12:15 PM · Difficulty 10.3548 · 6,363,856 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
ee8bd116c9c081bf8b4ea94bbde59cdb41bd2d956a6effe0cc86981e0663e669

Height

#435,067

Difficulty

10.354763

Transactions

1

Size

936 B

Version

2

Bits

0a5ad1bb

Nonce

91,373

Timestamp

3/8/2014, 4:12:15 PM

Confirmations

6,363,856

Merkle Root

a79a39cda76cbd2eecb580bd0152efb654b26398026d3704cab8e7d02858120a
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.

6.556 × 10⁹⁶(97-digit number)
65565603721005714558…47442174136112767999
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
6.556 × 10⁹⁶(97-digit number)
65565603721005714558…47442174136112767999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.311 × 10⁹⁷(98-digit number)
13113120744201142911…94884348272225535999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
2.622 × 10⁹⁷(98-digit number)
26226241488402285823…89768696544451071999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
5.245 × 10⁹⁷(98-digit number)
52452482976804571646…79537393088902143999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.049 × 10⁹⁸(99-digit number)
10490496595360914329…59074786177804287999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
2.098 × 10⁹⁸(99-digit number)
20980993190721828658…18149572355608575999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
4.196 × 10⁹⁸(99-digit number)
41961986381443657317…36299144711217151999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
8.392 × 10⁹⁸(99-digit number)
83923972762887314634…72598289422434303999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.678 × 10⁹⁹(100-digit number)
16784794552577462926…45196578844868607999
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
3.356 × 10⁹⁹(100-digit number)
33569589105154925853…90393157689737215999
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:57,635,417 XPM·at block #6,798,922 · 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.