Block #499,714

2CCLength 11★★★☆☆

Cunningham Chain of the Second Kind · Discovered 4/18/2014, 6:05:43 PM · Difficulty 10.7945 · 6,305,952 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
f27359d726de4e5627ced3b55c42dcbeed8221ce13825f0656f0f3e12769d739

Height

#499,714

Difficulty

10.794531

Transactions

10

Size

3.35 KB

Version

2

Bits

0acb6661

Nonce

21,182,572

Timestamp

4/18/2014, 6:05:43 PM

Confirmations

6,305,952

Merkle Root

74e026e9d3a5458c34caac0e3794ee9508ca9b619b2ba534487b913e474a74a4
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.

3.242 × 10⁹⁸(99-digit number)
32427529453419573031…76339610038222243841
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
3.242 × 10⁹⁸(99-digit number)
32427529453419573031…76339610038222243841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
6.485 × 10⁹⁸(99-digit number)
64855058906839146063…52679220076444487681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.297 × 10⁹⁹(100-digit number)
12971011781367829212…05358440152888975361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
2.594 × 10⁹⁹(100-digit number)
25942023562735658425…10716880305777950721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
5.188 × 10⁹⁹(100-digit number)
51884047125471316850…21433760611555901441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.037 × 10¹⁰⁰(101-digit number)
10376809425094263370…42867521223111802881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
2.075 × 10¹⁰⁰(101-digit number)
20753618850188526740…85735042446223605761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
4.150 × 10¹⁰⁰(101-digit number)
41507237700377053480…71470084892447211521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
8.301 × 10¹⁰⁰(101-digit number)
83014475400754106961…42940169784894423041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
1.660 × 10¹⁰¹(102-digit number)
16602895080150821392…85880339569788846081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
11
2^10 × origin + 1
3.320 × 10¹⁰¹(102-digit number)
33205790160301642784…71760679139577692161
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 11 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
RareChain length 11

Approximately 1 in 1,000 blocks. Noteworthy discoveries.

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:57,689,406 XPM·at block #6,805,665 · 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.