Communities

Writing
Writing
Codidact Meta
Codidact Meta
The Great Outdoors
The Great Outdoors
Photography & Video
Photography & Video
Scientific Speculation
Scientific Speculation
Cooking
Cooking
Electrical Engineering
Electrical Engineering
Judaism
Judaism
Languages & Linguistics
Languages & Linguistics
Software Development
Software Development
Mathematics
Mathematics
Christianity
Christianity
Code Golf
Code Golf
Music
Music
Physics
Physics
Linux Systems
Linux Systems
Power Users
Power Users
Tabletop RPGs
Tabletop RPGs
Community Proposals
Community Proposals
tag:snake search within a tag
answers:0 unanswered questions
user:xxxx search by author id
score:0.5 posts with 0.5+ score
"snake oil" exact phrase
votes:4 posts with 4+ votes
created:<1w created < 1 week ago
post_type:xxxx type of post
Search help
Notifications
Mark all as read See all your notifications »

Review Suggested Edit

You can't approve or reject suggested edits because you haven't yet earned the Edit Posts ability.

Approved.
This suggested edit was approved and applied to the post over 2 years ago by Razetime‭.

0 / 255
The Ludic Numbers
  • The Ludic Numbers are a sequence that pops up when you apply the sieve of eratosthenes to the natural numbers, completely removing the numbers every iteration.
  • Here is how they are generated:
  • The Ludic numbers start with the lists:
  • ```
  • l = [1]
  • n = [2,3,4,5,6,7,8,9,10....]
  • ```
  • Every iteration, we take the first element `x` in `n`, add it to the list, and remove every `x`th number in `n`, including `x`.
  • ```
  • l = [1,2]
  • n = [3,5,7,9,11,...]
  • ```
  • By repeating this process an infinite number of times, we can get the full list of Ludic numbers.
  • # Challenge
  • For this sequence, you can
  • * Take an index \$n\$ and output the \$n^{th}\$ term, either 0 or 1 indexed.
  • * Take a positive integer \$n\$ and output the first \$n\$ terms.
  • * Output the whole sequence as an infinite list.
  • # Testcases
  • ```
  • 1 1
  • 2 2
  • 3 3
  • 4 5
  • 5 7
  • 6 11
  • 7 13
  • 8 17
  • 9 23
  • 10 25
  • 11 29
  • 12 37
  • 13 41
  • 14 43
  • 15 47
  • 16 53
  • ```
  • The first 56 values can be seen here: [A003309](http://oeis.org/A003309/list).
  • Reference implementations can be found at [Rosetta Code](https://rosettacode.org/wiki/Ludic_numbers).
  • # Scoring
  • This is code-golf. Shortest answer in every language wins.
  • The Ludic Numbers are a sequence that pops up when you apply the sieve of eratosthenes to the natural numbers, completely removing the numbers every iteration.
  • Here is how they are generated:
  • The Ludic numbers start with the lists:
  • ```
  • l = [1]
  • n = [2,3,4,5,6,7,8,9,10....]
  • ```
  • Every iteration, we take the first element `x` in `n`, add it to the list, and remove every `x`th number in `n`, including `x`.
  • ```
  • l = [1,2]
  • n = [3,5,7,9,11,...]
  • ```
  • By repeating this process an infinite number of times, we can get the full list of Ludic numbers.
  • # Challenge
  • For this sequence, you can
  • * Take an index \$n\$ and output the \$n^{th}\$ term, either 0 or 1 indexed.
  • * Take a positive integer \$n\$ and output the first \$n\$ terms.
  • * Output the whole sequence as an infinite list.
  • # Testcases
  • ```
  • 1 1
  • 2 2
  • 3 3
  • 4 5
  • 5 7
  • 6 11
  • 7 13
  • 8 17
  • 9 23
  • 10 25
  • 11 29
  • 12 37
  • 13 41
  • 14 43
  • 15 47
  • 16 53
  • ```
  • The first 56 values can be seen here: [A003309](http://oeis.org/A003309/list).
  • Reference implementations can be found at [Rosetta Code](https://rosettacode.org/wiki/Ludic_numbers).
  • # Scoring
  • This is <a class="badge is-tag">code-golf</a>. Shortest answer in every language wins.

Suggested over 2 years ago by General Sebast1an‭