A047591 - OEIS

A047591

Numbers that are congruent to {1, 6, 7} mod 8.

1, 6, 7, 9, 14, 15, 17, 22, 23, 25, 30, 31, 33, 38, 39, 41, 46, 47, 49, 54, 55, 57, 62, 63, 65, 70, 71, 73, 78, 79, 81, 86, 87, 89, 94, 95, 97, 102, 103, 105, 110, 111, 113, 118, 119, 121, 126, 127, 129, 134, 135, 137, 142, 143, 145, 150, 151, 153, 158, 159

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OFFSET

1,2

LINKS

Table of n, a(n) for n=1..60.

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

FORMULA

From Wesley Ivan Hurt, Jun 09 2016: (Start)

G.f.: x*(1+5*x+x^2+x^3)/((x-1)^2*(1+x+x^2)).

a(n) = a(n-1) + a(n-3) - a(n-4) for n>4.

a(n) = (24*n-6-3*cos(2*n*Pi/3)-7*sqrt(3)*sin(2*n*Pi/3))/9.

a(3k) = 8k-1, a(3k-1) = 8k-2, a(3k-2) = 8k-7. (End)