oeis2

Haskell interface for Online Encyclopedia of Integer Sequences; homage to oeis.

Difference from oeis

• Source data of OEIS.
  : oeis use fmt=text, but this library use fmt=json.
• Possible to get all search results.
• Search functions from ID or sub-sequence are merged.
• Possibele to search from other than ID or sub-sequence.
• Support for HTTPS.

Usage

Add import statement.

import Math.OEIS

• Get all search results from sub-sequence

  • If n == 0, you get all search results.

    ghci>searchSeq (SubSeq [1,2,3,4]) 0
    [OEIS {number = "A000027", ids = ["M0472","N0173"], seqData = [1,2,3,4,5,6,7,...
    ghci>length it
    53

  • Otherwise, you get first n search results.

    ghci>searchSeq (SubSeq [1,2,3,4]) 17
    [OEIS {number = "A000027", ids = ["M0472","N0173"], seqData = [1,2,3,4,5,6,7,8,9,
    ghci>length it
    17

• Get first few terms from sub-sequence

  ghci>getSeqData (SubSeq [1,2,2,3,3,3,4,4,4,4])
  Just [1,2,2,3,3,3,4,4,4,4,5,5,5,5,5,6,6,6,6,6,6,7,7,7,7,7,7,7,...

• Get Mathematica function from sub-sequence

  ghci>mathematica <$> lookupSeq (SubSeq [1,2,2,3,3,3,4,4,4,4])
  Just ["a[1] = 1; a[n_] := a[n] = a[n - a[n - 1]] + 1 (* _Branko Curgus_, May 12 2009 *)","Table[n, {n, 13}, {n}] // Flatten (* _Robert G. Wilson v_, May 11 2010 *)"]

• If no search result

  ghci>lookupSeq (ID "1145141919893")
  Nothing