A047319 Numbers that are congruent to {5, 6} mod 7.

5, 6, 12, 13, 19, 20, 26, 27, 33, 34, 40, 41, 47, 48, 54, 55, 61, 62, 68, 69, 75, 76, 82, 83, 89, 90, 96, 97, 103, 104, 110, 111, 117, 118, 124, 125, 131, 132, 138, 139, 145, 146, 152, 153, 159, 160, 166, 167, 173

Offset

1,1

Links

David Lovler, Table of n, a(n) for n = 1..1000

Index entries for linear recurrences with constant coefficients, signature (1,1,-1).

Formula

From R. J. Mathar, Oct 08 2011: (Start)

a(n) = 1/4 + 7*n/2 - 5*(-1)^n/4.

G.f.: x*(5 + x + x^2) / ( (1+x)*(x-1)^2 ). (End)

E.g.f.: 1 + ((14*x + 1)*exp(x) - 5*exp(-x))/4. - David Lovler, Sep 26 2022

Prog

(PARI) a(n) = (14*n + 1 - 5*(-1)^n)/4 \\ David Lovler, Sep 26 2022

Crossrefs

Sequence in context: A099641 A207189 A285404 * A244368 A185031 A138925

Adjacent sequences: A047316 A047317 A047318 * A047320 A047321 A047322

Keyword

nonn,easy

Author

N. J. A. Sloane

Status

approved