Block #476,634

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 4/5/2014, 10:58:56 PM · Difficulty 10.4754 · 6,341,114 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
6e86ca34a78f70acf161250bcbd50d8ff7a1e199c504cf8649026ea57eceb917

Height

#476,634

Difficulty

10.475402

Transactions

1

Size

900 B

Version

2

Bits

0a79b3f7

Nonce

254,578

Timestamp

4/5/2014, 10:58:56 PM

Confirmations

6,341,114

Merkle Root

3408d17ec75c82b8a332747e97776c38f5b3969292c4452730e6833f30902c84
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.

2.121 × 10⁹²(93-digit number)
21217901341292257157…38260735105744877379
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
2.121 × 10⁹²(93-digit number)
21217901341292257157…38260735105744877379
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
4.243 × 10⁹²(93-digit number)
42435802682584514315…76521470211489754759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
8.487 × 10⁹²(93-digit number)
84871605365169028630…53042940422979509519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.697 × 10⁹³(94-digit number)
16974321073033805726…06085880845959019039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
3.394 × 10⁹³(94-digit number)
33948642146067611452…12171761691918038079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
6.789 × 10⁹³(94-digit number)
67897284292135222904…24343523383836076159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.357 × 10⁹⁴(95-digit number)
13579456858427044580…48687046767672152319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
2.715 × 10⁹⁴(95-digit number)
27158913716854089161…97374093535344304639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
5.431 × 10⁹⁴(95-digit number)
54317827433708178323…94748187070688609279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.086 × 10⁹⁵(96-digit number)
10863565486741635664…89496374141377218559
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:57,786,038 XPM·at block #6,817,747 · updates every 60s
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