Block #470,813

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 4/2/2014, 4:35:53 AM · Difficulty 10.4288 · 6,335,351 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
a87752c234f927f1fb00a0f295baf4b11430ed1344f3cdce9c0a73594cfce949

Height

#470,813

Difficulty

10.428793

Transactions

4

Size

1.58 KB

Version

2

Bits

0a6dc564

Nonce

76,995

Timestamp

4/2/2014, 4:35:53 AM

Confirmations

6,335,351

Merkle Root

0cad27d2f4bef1dfc4f5e241a971fa25f7de1aac596cf77eac083b96deb8cf6a
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.

4.381 × 10⁹⁷(98-digit number)
43816677276296178515…74700693949651565599
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
4.381 × 10⁹⁷(98-digit number)
43816677276296178515…74700693949651565599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
8.763 × 10⁹⁷(98-digit number)
87633354552592357030…49401387899303131199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.752 × 10⁹⁸(99-digit number)
17526670910518471406…98802775798606262399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
3.505 × 10⁹⁸(99-digit number)
35053341821036942812…97605551597212524799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
7.010 × 10⁹⁸(99-digit number)
70106683642073885624…95211103194425049599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.402 × 10⁹⁹(100-digit number)
14021336728414777124…90422206388850099199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
2.804 × 10⁹⁹(100-digit number)
28042673456829554249…80844412777700198399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
5.608 × 10⁹⁹(100-digit number)
56085346913659108499…61688825555400396799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.121 × 10¹⁰⁰(101-digit number)
11217069382731821699…23377651110800793599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
2.243 × 10¹⁰⁰(101-digit number)
22434138765463643399…46755302221601587199
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:57,693,394 XPM·at block #6,806,163 · 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.