Block #469,502

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 4/1/2014, 6:56:30 AM · Difficulty 10.4270 · 6,331,940 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
839790b2d8b05adab1f6495ebe416f464e5ff565a2fe4feabb192f2c05afac6a

Height

#469,502

Difficulty

10.427014

Transactions

4

Size

1.25 KB

Version

2

Bits

0a6d50ce

Nonce

33,164

Timestamp

4/1/2014, 6:56:30 AM

Confirmations

6,331,940

Merkle Root

e99c79973f02d2dc81221cc2e0f064696c70122686738a87b411fe1d113af4dd
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.

6.347 × 10⁹⁸(99-digit number)
63477699409276382788…12996091126817721599
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
6.347 × 10⁹⁸(99-digit number)
63477699409276382788…12996091126817721599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.269 × 10⁹⁹(100-digit number)
12695539881855276557…25992182253635443199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
2.539 × 10⁹⁹(100-digit number)
25391079763710553115…51984364507270886399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
5.078 × 10⁹⁹(100-digit number)
50782159527421106230…03968729014541772799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.015 × 10¹⁰⁰(101-digit number)
10156431905484221246…07937458029083545599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
2.031 × 10¹⁰⁰(101-digit number)
20312863810968442492…15874916058167091199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
4.062 × 10¹⁰⁰(101-digit number)
40625727621936884984…31749832116334182399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
8.125 × 10¹⁰⁰(101-digit number)
81251455243873769969…63499664232668364799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.625 × 10¹⁰¹(102-digit number)
16250291048774753993…26999328465336729599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
3.250 × 10¹⁰¹(102-digit number)
32500582097549507987…53998656930673459199
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:57,655,609 XPM·at block #6,801,441 · updates every 60s
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