Block #365,047

1CCLength 11★★★☆☆

Cunningham Chain of the First Kind · Discovered 1/18/2014, 11:47:30 AM · Difficulty 10.4234 · 6,437,459 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
4e7174923a7a37b0f15bf6b3dd55235d8cf6379575c74f3c6b67a9e1a8ae1a92

Height

#365,047

Difficulty

10.423384

Transactions

5

Size

3.80 KB

Version

2

Bits

0a6c62e9

Nonce

127,251

Timestamp

1/18/2014, 11:47:30 AM

Confirmations

6,437,459

Merkle Root

8f791d12a2e002f182ffb788a68ff741c8c0f75a4152052e04c42d7101c266fd
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.

3.472 × 10⁹⁹(100-digit number)
34728830164374988342…35366369226034375679
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
3.472 × 10⁹⁹(100-digit number)
34728830164374988342…35366369226034375679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
6.945 × 10⁹⁹(100-digit number)
69457660328749976684…70732738452068751359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.389 × 10¹⁰⁰(101-digit number)
13891532065749995336…41465476904137502719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
2.778 × 10¹⁰⁰(101-digit number)
27783064131499990673…82930953808275005439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
5.556 × 10¹⁰⁰(101-digit number)
55566128262999981347…65861907616550010879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.111 × 10¹⁰¹(102-digit number)
11113225652599996269…31723815233100021759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
2.222 × 10¹⁰¹(102-digit number)
22226451305199992539…63447630466200043519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
4.445 × 10¹⁰¹(102-digit number)
44452902610399985078…26895260932400087039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
8.890 × 10¹⁰¹(102-digit number)
88905805220799970156…53790521864800174079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.778 × 10¹⁰²(103-digit number)
17781161044159994031…07581043729600348159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
11
2^10 × origin − 1
3.556 × 10¹⁰²(103-digit number)
35562322088319988062…15162087459200696319
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 11 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
RareChain length 11

Approximately 1 in 1,000 blocks. Noteworthy discoveries.

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:57,664,055 XPM·at block #6,802,505 · updates every 60s
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