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.

A112055 a(n) = A112054(n)/6.

Original entry on oeis.org

2, 3, 5, 7, 8, 12, 13, 15, 17, 18, 20, 22, 23, 27, 28, 30, 32, 33, 35, 37, 38, 40, 42, 43, 47, 48, 50, 52, 53, 55, 57, 58, 62, 63, 65, 67, 68, 70, 72, 73, 75, 77, 78, 82, 83, 85, 87, 88, 90, 92, 93, 97, 98, 100, 102, 103, 107, 108, 110, 112, 113, 117, 118, 120, 122
Offset: 1

Views

Author

Antti Karttunen, Aug 27 2005

Keywords

Crossrefs

Cf. A112054, A112082 (complement), A112085 (first differences).

Programs

  • Mathematica
    a112046[n_]:=Block[{i=1}, While[JacobiSymbol[i, 2n + 1]==1, i++]; i]; Select[Range[1000], a112046[2#] - a112046[2# - 1] != 0 &]/6 (* Indranil Ghosh, May 25 2017 *)
  • Python
    from sympy import jacobi_symbol as J
    def a112046(n):
        i=1
        while True:
            if J(i, 2*n + 1)!=1: return i
            else: i+=1
    def a(n): return a112046(2*n) - a112046(2*n - 1)
    print([n//6 for n in range(1, 201) if a(n)!=0]) # Indranil Ghosh, May 25 2017