Block #459,863

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 3/25/2014, 2:25:21 PM · Difficulty 10.4213 · 6,343,897 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
221c8e207a764db8f6080b9d87051e23370b7761916bb900384c62c0a376f417

Height

#459,863

Difficulty

10.421331

Transactions

8

Size

2.68 KB

Version

2

Bits

0a6bdc52

Nonce

52,875

Timestamp

3/25/2014, 2:25:21 PM

Confirmations

6,343,897

Merkle Root

e4994e4442aa8c03061f38a1223f721b2423f000cebda72add743acbada24114
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.

2.691 × 10⁹⁷(98-digit number)
26911469626711434042…89251635783379444001
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
2.691 × 10⁹⁷(98-digit number)
26911469626711434042…89251635783379444001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
5.382 × 10⁹⁷(98-digit number)
53822939253422868084…78503271566758888001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.076 × 10⁹⁸(99-digit number)
10764587850684573616…57006543133517776001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
2.152 × 10⁹⁸(99-digit number)
21529175701369147233…14013086267035552001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
4.305 × 10⁹⁸(99-digit number)
43058351402738294467…28026172534071104001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
8.611 × 10⁹⁸(99-digit number)
86116702805476588935…56052345068142208001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
1.722 × 10⁹⁹(100-digit number)
17223340561095317787…12104690136284416001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
3.444 × 10⁹⁹(100-digit number)
34446681122190635574…24209380272568832001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
6.889 × 10⁹⁹(100-digit number)
68893362244381271148…48418760545137664001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
1.377 × 10¹⁰⁰(101-digit number)
13778672448876254229…96837521090275328001
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:57,674,120 XPM·at block #6,803,759 · 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.