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.

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A112080 a(n) = difference between Jacobi-first-non-one(24n+1) and Jacobi-first-non-one(24n-1).

Original entry on oeis.org

0, 2, -2, 0, 4, 0, 8, -2, 0, 0, 0, 12, -6, 0, 12, 0, 2, -2, 0, -6, 0, 18, -6, 0, 0, 0, 2, -6, 0, -4, 0, 2, -2, 0, 18, 0, 2, -2, 0, 24, 0, 6, -2, 0, 0, 0, 6, -8, 0, 4, 0, 2, -2, 0, -6, 0, 32, -6, 0, 0, 0, 2, -6, 0, -10, 0, 2, -2, 0, 28, 0, 2, -2, 0, 4, 0, 38, -2, 0, 0, 0, 6, -6, 0, 4, 0, 2
Offset: 1

Views

Author

Antti Karttunen, Aug 27 2005

Keywords

Comments

The definition of Jacobi-first-non-one is given in A112056.

Crossrefs

A112081(n) = a(n)/2. A112082 gives the points where a(n) is zero. A112059 gives the nonzero terms.

Formula

a(n) = 4*A112054(n)+1.

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
Showing 1-2 of 2 results.