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A047236 Numbers that are congruent to {1, 2, 4} mod 6. 4
1, 2, 4, 7, 8, 10, 13, 14, 16, 19, 20, 22, 25, 26, 28, 31, 32, 34, 37, 38, 40, 43, 44, 46, 49, 50, 52, 55, 56, 58, 61, 62, 64, 67, 68, 70, 73, 74, 76, 79, 80, 82, 85, 86, 88, 91, 92, 94, 97, 98, 100, 103, 104, 106, 109, 110, 112, 115, 116, 118, 121, 122, 124 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..63.

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

FORMULA

G.f.: x*(1+x)*(2*x^2+1)/((1+x+x^2)*(x-1)^2). - R. J. Mathar, Oct 08 2011

From Wesley Ivan Hurt, Jun 10 2016: (Start)

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

a(n) = (6*n-5-cos(2*n*Pi/3)+sqrt(3)*sin(2*n*Pi/3))/3.

a(3k) = 6k-2, a(3k-1) = 6k-4, a(3k-2) = 6k-5. (End)

MAPLE

A047236:=n->(6*n-5-cos(2*n*Pi/3)+sqrt(3)*sin(2*n*Pi/3))/3: seq(A047236(n), n=1..100); # Wesley Ivan Hurt, Jun 10 2016

MATHEMATICA

Select[Range[0, 150], MemberQ[{1, 2, 4}, Mod[#, 6]] &] (* Wesley Ivan Hurt, Jun 10 2016 *)

PROG

(MAGMA) [n : n in [0..150] | n mod 6 in [1, 2, 4]]; // Wesley Ivan Hurt, Jun 10 2016

CROSSREFS

Sequence in context: A116478 A207829 A207827 * A039581 A338420 A182218

Adjacent sequences:  A047233 A047234 A047235 * A047237 A047238 A047239

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane

STATUS

approved

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Last modified May 12 13:02 EDT 2021. Contains 343823 sequences. (Running on oeis4.)