Block #315,112

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 12/16/2013, 8:34:31 AM · Difficulty 10.0843 · 6,479,650 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
b1e9ec63eaf96032410acd7f9bf18b0b1aeefb12b7631971f30f51e4cfc91b32

Height

#315,112

Difficulty

10.084339

Transactions

18

Size

18.07 KB

Version

2

Bits

0a159738

Nonce

66,202

Timestamp

12/16/2013, 8:34:31 AM

Confirmations

6,479,650

Merkle Root

84a1d88bab46a085498304c288702099a11182b0f90affd39fc9a5253a2d01f0
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.

9.482 × 10¹⁰¹(102-digit number)
94827602074109850875…93372061726371774719
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
9.482 × 10¹⁰¹(102-digit number)
94827602074109850875…93372061726371774719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.896 × 10¹⁰²(103-digit number)
18965520414821970175…86744123452743549439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
3.793 × 10¹⁰²(103-digit number)
37931040829643940350…73488246905487098879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
7.586 × 10¹⁰²(103-digit number)
75862081659287880700…46976493810974197759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.517 × 10¹⁰³(104-digit number)
15172416331857576140…93952987621948395519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
3.034 × 10¹⁰³(104-digit number)
30344832663715152280…87905975243896791039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
6.068 × 10¹⁰³(104-digit number)
60689665327430304560…75811950487793582079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.213 × 10¹⁰⁴(105-digit number)
12137933065486060912…51623900975587164159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
2.427 × 10¹⁰⁴(105-digit number)
24275866130972121824…03247801951174328319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
4.855 × 10¹⁰⁴(105-digit number)
48551732261944243648…06495603902348656639
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:57,602,144 XPM·at block #6,794,761 · updates every 60s
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