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.

A047434 Numbers that are congruent to {0, 2, 4, 5, 6} mod 8.

Original entry on oeis.org

0, 2, 4, 5, 6, 8, 10, 12, 13, 14, 16, 18, 20, 21, 22, 24, 26, 28, 29, 30, 32, 34, 36, 37, 38, 40, 42, 44, 45, 46, 48, 50, 52, 53, 54, 56, 58, 60, 61, 62, 64, 66, 68, 69, 70, 72, 74, 76, 77, 78, 80, 82, 84, 85, 86, 88, 90, 92, 93, 94, 96, 98, 100, 101, 102
Offset: 1

Views

Author

Keywords

Programs

  • Magma
    [n : n in [0..150] | n mod 8 in [0, 2, 4, 5, 6]]; // Wesley Ivan Hurt, Aug 01 2016
  • Maple
    A047434:=n->8*floor(n/5)+[(0, 2, 4, 5, 6)][(n mod 5)+1]: seq(A047434(n), n=0..100); # Wesley Ivan Hurt, Aug 01 2016
  • Mathematica
    Select[Range[0, 100], MemberQ[{0, 2, 4, 5, 6}, Mod[#, 8]] &] (* Wesley Ivan Hurt, Aug 01 2016 *)

Formula

G.f.: x^2*(2+2*x+x^2+x^3+2*x^4) / ( (x^4+x^3+x^2+x+1)*(x-1)^2 ). - R. J. Mathar, Dec 07 2011
From Wesley Ivan Hurt, Aug 01 2016: (Start)
a(n) = a(n-1) + a(n-5) - a(n-6) for n > 6, a(n) = a(n-5) + 8 for n > 5.
a(n) = (40*n - 35 + 3*(n mod 5) + 3*((n+1) mod 5) - 2*((n+2) mod 5) - 2*((n+3) mod 5) - 2*((n+4) mod 5))/25.
a(5k) = 8k-2, a(5k-1) = 8k-3, a(5k-2) = 8k-4, a(5k-3) = 8k-6, a(5k-4) = 8k-8. (End)