Block #317,898

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 12/18/2013, 12:19:29 AM · Difficulty 10.1552 · 6,487,035 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
096abff22be683be73543bc20be984f9d1e608cf4480b40f078e07969a28c4bc

Height

#317,898

Difficulty

10.155182

Transactions

30

Size

8.61 KB

Version

2

Bits

0a27ba04

Nonce

117,761

Timestamp

12/18/2013, 12:19:29 AM

Confirmations

6,487,035

Merkle Root

5219b40a4254b35d341dffbc5820ba285bd8c8a000bf2e09c2511d6ad53442bb
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.

3.597 × 10⁹⁵(96-digit number)
35971005108990102847…37046314410189364799
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
3.597 × 10⁹⁵(96-digit number)
35971005108990102847…37046314410189364799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
7.194 × 10⁹⁵(96-digit number)
71942010217980205694…74092628820378729599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.438 × 10⁹⁶(97-digit number)
14388402043596041138…48185257640757459199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
2.877 × 10⁹⁶(97-digit number)
28776804087192082277…96370515281514918399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
5.755 × 10⁹⁶(97-digit number)
57553608174384164555…92741030563029836799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.151 × 10⁹⁷(98-digit number)
11510721634876832911…85482061126059673599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
2.302 × 10⁹⁷(98-digit number)
23021443269753665822…70964122252119347199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
4.604 × 10⁹⁷(98-digit number)
46042886539507331644…41928244504238694399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
9.208 × 10⁹⁷(98-digit number)
92085773079014663288…83856489008477388799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.841 × 10⁹⁸(99-digit number)
18417154615802932657…67712978016954777599
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:57,683,537 XPM·at block #6,804,932 · updates every 60s
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