Block #283,083

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 11/29/2013, 2:54:40 PM · Difficulty 9.9804 · 6,513,477 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
8f483b6c26f8c05d954e575637de78d2c833936b312f4de4ee5f6977ee5618b0

Height

#283,083

Difficulty

9.980425

Transactions

7

Size

3.68 KB

Version

2

Bits

09fafd22

Nonce

4,098

Timestamp

11/29/2013, 2:54:40 PM

Confirmations

6,513,477

Merkle Root

da22cb7320335bb8a8e8854534ee4d203aec05df827815eef121f95016081d7e
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.

9.002 × 10¹⁰⁰(101-digit number)
90026003045395473891…19500291806558901849
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
9.002 × 10¹⁰⁰(101-digit number)
90026003045395473891…19500291806558901849
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.800 × 10¹⁰¹(102-digit number)
18005200609079094778…39000583613117803699
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
3.601 × 10¹⁰¹(102-digit number)
36010401218158189556…78001167226235607399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
7.202 × 10¹⁰¹(102-digit number)
72020802436316379113…56002334452471214799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
1.440 × 10¹⁰²(103-digit number)
14404160487263275822…12004668904942429599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
2.880 × 10¹⁰²(103-digit number)
28808320974526551645…24009337809884859199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
5.761 × 10¹⁰²(103-digit number)
57616641949053103290…48018675619769718399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
1.152 × 10¹⁰³(104-digit number)
11523328389810620658…96037351239539436799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
2.304 × 10¹⁰³(104-digit number)
23046656779621241316…92074702479078873599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
4.609 × 10¹⁰³(104-digit number)
46093313559242482632…84149404958157747199
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:57,616,479 XPM·at block #6,796,559 · updates every 60s
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