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.

Showing 1-2 of 2 results.

A047342 Numbers that are congruent to {0, 3, 4} mod 7.

Original entry on oeis.org

0, 3, 4, 7, 10, 11, 14, 17, 18, 21, 24, 25, 28, 31, 32, 35, 38, 39, 42, 45, 46, 49, 52, 53, 56, 59, 60, 63, 66, 67, 70, 73, 74, 77, 80, 81, 84, 87, 88, 91, 94, 95, 98, 101, 102, 105, 108, 109, 112, 115, 116, 119, 122, 123, 126, 129, 130, 133, 136, 137, 140
Offset: 1

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Author

Keywords

Comments

Record values in A168223: a(n) = A168223(A168224(n)) and A168223(m) < a(n) for m < A168224(n). - Reinhard Zumkeller, Nov 20 2009
Also: Numbers n such that kronecker(n^2-4,7) = -1. - M. F. Hasler, Mar 14 2013

Crossrefs

Programs

Formula

G.f.: x(3+x+3x^2)/((1-x)^2*(1+x+x^2)). - R. J. Mathar, Sep 17 2008
a(n) = a(n-1) + a(n-3) - a(n-4), n>4. - Vincenzo Librandi, Mar 24 2011
From Wesley Ivan Hurt, Jun 13 2016: (Start)
a(n) = (21*n-21-6*cos(2*n*Pi/3)-2*sqrt(3)*sin(2*n*Pi/3))/9.
a(3k) = 7k-3, a(3k-1) = 7k-4, a(3k-2) = 7k-7. (End)

A168223 a(n) = A006369(n) - A006368(n).

Original entry on oeis.org

0, 0, 0, 0, -1, 3, -5, 4, -1, -1, -2, 7, -10, 7, -2, -1, -3, 10, -15, 11, -3, -2, -4, 14, -20, 14, -4, -2, -5, 17, -25, 18, -5, -3, -6, 21, -30, 21, -6, -3, -7, 24, -35, 25, -7, -4, -8, 28, -40, 28, -8, -4, -9, 31, -45, 32, -9, -5, -10, 35, -50, 35, -10, -5, -11, 38, -55, 39
Offset: 0

Views

Author

Reinhard Zumkeller, Nov 20 2009

Keywords

Comments

A047342 and A168223 give record values and where they occur: a(A168224(n))=A047342(n) and a(m) < A047342(n) for m < A168224(n).

Programs

  • Haskell
    a168223 n = a006369 n - a006368 n  -- Reinhard Zumkeller, Mar 15 2014
  • Mathematica
    LinearRecurrence[{-2,-2,0,3,4,3,0,-2,-2,-1},{0, 0, 0, 0, -1, 3, -5, 4, -1, -1},50] (* G. C. Greubel, Jul 16 2016 *)

Formula

a(12*n) = -10*n, a(12*n+1) = 7*n.
a(12*n+2) = -2*n, a(12*n+3) = -n.
a(12*n+4) = -2*n - 1, a(12*n+5) = 7*n + 3.
a(12*n+6) = -10*n - 5, a(12*n+7) = 7*n + 4.
a(12*n+8) = -2*n -1, a(12*n+9) = -n - 1.
a(12*n+10) = -2*n - 2, a(12*n+11) = 7*n + 7.
G.f.: -x^4*(x^2-x+1) / ((x-1)^2*(x+1)^2*(x^2+1)*(x^2+x+1)^2). - Colin Barker, Apr 04 2013
Showing 1-2 of 2 results.