Block #424,727

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 3/1/2014, 10:05:33 AM · Difficulty 10.3623 · 6,369,855 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
cbf025e44f44ba912311ae4b8e59726a4b3a33a19c74cb47ea47cc0bbb06548e

Height

#424,727

Difficulty

10.362313

Transactions

9

Size

3.93 KB

Version

2

Bits

0a5cc090

Nonce

83,756

Timestamp

3/1/2014, 10:05:33 AM

Confirmations

6,369,855

Merkle Root

d17b2b9434510106e7a0805fdfbe62ae2cf0484cc6a8c36834ec0703dbbf58e2
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.

3.268 × 10¹⁰³(104-digit number)
32689520442610552652…89572396716272394239
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
3.268 × 10¹⁰³(104-digit number)
32689520442610552652…89572396716272394239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
6.537 × 10¹⁰³(104-digit number)
65379040885221105305…79144793432544788479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.307 × 10¹⁰⁴(105-digit number)
13075808177044221061…58289586865089576959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
2.615 × 10¹⁰⁴(105-digit number)
26151616354088442122…16579173730179153919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
5.230 × 10¹⁰⁴(105-digit number)
52303232708176884244…33158347460358307839
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.046 × 10¹⁰⁵(106-digit number)
10460646541635376848…66316694920716615679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
2.092 × 10¹⁰⁵(106-digit number)
20921293083270753697…32633389841433231359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
4.184 × 10¹⁰⁵(106-digit number)
41842586166541507395…65266779682866462719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
8.368 × 10¹⁰⁵(106-digit number)
83685172333083014791…30533559365732925439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.673 × 10¹⁰⁶(107-digit number)
16737034466616602958…61067118731465850879
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:57,600,703 XPM·at block #6,794,581 · updates every 60s
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