Block #335,973

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 12/30/2013, 3:27:52 PM · Difficulty 10.1436 · 6,480,526 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
ec8d241d0cc86a04e389c2d1f81a8a77ab7cef0440b672fb4b411c14f163b0eb

Height

#335,973

Difficulty

10.143578

Transactions

1

Size

936 B

Version

2

Bits

0a24c184

Nonce

451,397

Timestamp

12/30/2013, 3:27:52 PM

Confirmations

6,480,526

Merkle Root

fbd1878cb27741da5aa73dc48ad173458aa071867d65fb55249b5bb14561f3a3
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.

4.200 × 10⁹⁶(97-digit number)
42006789780995814879…20292610830220587699
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
4.200 × 10⁹⁶(97-digit number)
42006789780995814879…20292610830220587699
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
8.401 × 10⁹⁶(97-digit number)
84013579561991629758…40585221660441175399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.680 × 10⁹⁷(98-digit number)
16802715912398325951…81170443320882350799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
3.360 × 10⁹⁷(98-digit number)
33605431824796651903…62340886641764701599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
6.721 × 10⁹⁷(98-digit number)
67210863649593303806…24681773283529403199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.344 × 10⁹⁸(99-digit number)
13442172729918660761…49363546567058806399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
2.688 × 10⁹⁸(99-digit number)
26884345459837321522…98727093134117612799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
5.376 × 10⁹⁸(99-digit number)
53768690919674643045…97454186268235225599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.075 × 10⁹⁹(100-digit number)
10753738183934928609…94908372536470451199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
2.150 × 10⁹⁹(100-digit number)
21507476367869857218…89816745072940902399
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:57,776,121 XPM·at block #6,816,498 · updates every 60s
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