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.

A143234 a(n) = sqrt(2^(-n)*A004003(n)) mod 32.

Original entry on oeis.org

1, 1, 3, 29, 5, 5, 7, 25, 9, 9, 11, 21, 13, 13, 15, 17, 17, 17, 19, 13, 21, 21, 23, 9, 25, 25, 27, 5, 29, 29, 31, 1, 1, 1, 3, 29, 5, 5, 7, 25, 9, 9, 11, 21, 13, 13, 15, 17, 17, 17, 19, 13, 21, 21, 23, 9, 25, 25, 27, 5, 29, 29, 31, 1, 1, 1, 3, 29, 5, 5, 7, 25, 9, 9, 11, 21, 13, 13, 15, 17
Offset: 0

Views

Author

Eric W. Weisstein, Jul 31 2008

Keywords

Crossrefs

Programs

  • Magma
    A143234:= func< n | (-1)^(0^((n+1) mod 4))*(2*Floor(n/2) + 1) mod 32 >;
    [A143234(n): n in [0..100]]; // G. C. Greubel, Sep 11 2024
    
  • Mathematica
    (* First program *)
    a[n_]:= Mod[If[EvenQ[n], n + 1, (-1)^((n-1)/2)*n], 32];
    Table[a[n], {n,0,100}]
    (* Second program *)
    A143234[n_]:= Mod[(-1)^(Floor[Mod[n,4]/3])*(2*Floor[n/2]+1), 32];
    Table[A143234[n], {n,0,100}] (* G. C. Greubel, Sep 12 2024 *)
  • SageMath
    def A143234(n): return ((-1)^(0^((n+1)%4))*(2*int(n//2)+1))%32
    [A143234(n) for n in range(101)] # G. C. Greubel, Sep 11 2024

Formula

a(n) = A065072(n) mod 32.
From G. C. Greubel, Sep 12 2024: (Start)
a(n) = ( (-1)^A121262(n+1) * A109613(n) ) mod 32.
a(n) = a(n-32). (End)

Extensions

Offset changed by Editor(s) of Oeis.