cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A255833 Index i such that A166133(i)=n, or 0 if no such i exists.

Original entry on oeis.org

1, 2, 4, 3, 8, 7, 6, 5, 12, 11, 10, 9, 16, 15, 14, 13, 21, 20, 19, 18, 17, 24, 23, 22, 29, 28, 27, 26, 40, 39, 38, 37, 36, 35, 34, 33, 32, 31, 30, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 25
Offset: 1

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Author

M. F. Hasler, Apr 01 2015

Keywords

Comments

If A166133 is a permutation, as conjectured, then this is the inverse permutation.

Crossrefs

Programs

  • Haskell
    import Data.List (elemIndex); import Data.Maybe (fromJust)
    a255833 = (+ 1) . fromJust . (`elemIndex` a166133_list)
    -- Reinhard Zumkeller, Apr 02 2015
  • PARI
    a(n)=for(i=1,#a166133,a166133[i]==n&&return(i)) \\ assumes a166133 defined as a vector, e.g., via {c=0; a166133=apply(t->eval(concat(Vec(t)[1+#Str(c++) .. -1])), readstr("/tmp/b166133.txt"))}
    

Extensions

Definition simplified by Franklin T. Adams-Watters, Apr 01 2015