Block #487,501

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 4/12/2014, 4:35:28 AM · Difficulty 10.6418 · 6,306,041 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
d71de6ffb9624b8e0360277e4922b7be9e9f3f97a40f1794ca22debbc809dab3

Height

#487,501

Difficulty

10.641812

Transactions

3

Size

2.26 KB

Version

2

Bits

0aa44dc5

Nonce

227,730,676

Timestamp

4/12/2014, 4:35:28 AM

Confirmations

6,306,041

Merkle Root

2fca66c0e9d82616bcdb03d010cc3c046b127ae9fa6e025eec82da5e9da0f1e6
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.

3.830 × 10⁹⁷(98-digit number)
38304618845321172356…29144023782682943599
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
3.830 × 10⁹⁷(98-digit number)
38304618845321172356…29144023782682943599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
7.660 × 10⁹⁷(98-digit number)
76609237690642344712…58288047565365887199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.532 × 10⁹⁸(99-digit number)
15321847538128468942…16576095130731774399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
3.064 × 10⁹⁸(99-digit number)
30643695076256937884…33152190261463548799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
6.128 × 10⁹⁸(99-digit number)
61287390152513875769…66304380522927097599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.225 × 10⁹⁹(100-digit number)
12257478030502775153…32608761045854195199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
2.451 × 10⁹⁹(100-digit number)
24514956061005550307…65217522091708390399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
4.902 × 10⁹⁹(100-digit number)
49029912122011100615…30435044183416780799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
9.805 × 10⁹⁹(100-digit number)
98059824244022201231…60870088366833561599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.961 × 10¹⁰⁰(101-digit number)
19611964848804440246…21740176733667123199
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:57,592,331 XPM·at block #6,793,541 · updates every 60s
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