A131870 Period 8: repeat [1, 2, 3, 4, 6, 7, 8, 9].

1, 2, 3, 4, 6, 7, 8, 9, 1, 2, 3, 4, 6, 7, 8, 9, 1, 2, 3, 4, 6, 7, 8, 9, 1, 2, 3, 4, 6, 7, 8, 9, 1, 2, 3, 4, 6, 7, 8, 9, 1, 2, 3, 4, 6, 7, 8, 9, 1, 2, 3, 4, 6, 7, 8, 9, 1, 2, 3, 4, 6, 7, 8, 9, 1, 2, 3, 4, 6, 7, 8, 9, 1, 2, 3, 4, 6, 7, 8, 9, 1, 2, 3, 4, 6, 7, 8, 9, 1, 2, 3, 4, 6, 7, 8, 9, 1, 2, 3, 4, 6, 7, 8, 9, 1

Offset

0,2

Links

Table of n, a(n) for n=0..104.

Index entries for linear recurrences with constant coefficients, signature (0,0,0,0,0,0,0,1).

Formula

From Wesley Ivan Hurt, Aug 31 2019: (Start)

G.f.: (1 + 2*x + 3*x^2 + 4*x^3 + 6*x^4 + 7*x^5 + 8*x^6 + 9*x^7)/(1-x^8).

a(n) = (1+(n mod 4))*(1+(-1)^floor(n/4))/2 + (6+((n-4) mod 4))*(1+(-1)^floor((n-4)/4))/2.

(End)

Mathematica

CoefficientList[Series[(1 + 2*x + 3*x^2 + 4*x^3 + 6*x^4 + 7*x^5 + 8*x^6 + 9*x^7)/(1 - x^8), {x, 0, 80}], x] (* Wesley Ivan Hurt, Aug 31 2019 *)
PadRight[{}, 120, {1, 2, 3, 4, 6, 7, 8, 9}] (* Harvey P. Dale, Aug 17 2021 *)

Prog

(PARI) a(n)=n=n%8; if(n>3, 2, 1)+n \\ Charles R Greathouse IV, Jul 13 2016

Crossrefs

Cf. A071789.

Sequence in context: A175059 A366429 A071789 * A004724 A099260 A231237

Adjacent sequences: A131867 A131868 A131869 * A131871 A131872 A131873

Keyword

nonn,easy

Author

Paul Curtz, Oct 05 2007

Status

approved