

A047249


Numbers that are congruent to {3, 4, 5} mod 6.


1



3, 4, 5, 9, 10, 11, 15, 16, 17, 21, 22, 23, 27, 28, 29, 33, 34, 35, 39, 40, 41, 45, 46, 47, 51, 52, 53, 57, 58, 59, 63, 64, 65, 69, 70, 71, 75, 76, 77, 81, 82, 83, 87, 88, 89, 93, 94, 95, 99, 100, 101, 105, 106, 107, 111, 112, 113, 117, 118, 119, 123, 124
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OFFSET

1,1


LINKS

Table of n, a(n) for n=1..62.
Index entries for linear recurrences with constant coefficients, signature (1,0,1,1).


FORMULA

G.f.: x*(3+x+x^2+x^3) / ((1+x+x^2)*(x1)^2).  R. J. Mathar, Oct 08 2011
From Wesley Ivan Hurt, Jun 10 2016: (Start)
a(n) = a(n1) + a(n3)  a(n4) for n>4.
a(n) = 2*ncos(2*n*Pi/3)+sin(2*n*Pi/3)/sqrt(3).
a(3k) = 6k1, a(3k1) = 6k2, a(3k2) = 6k3. (End)


MAPLE

A047249:=n>2*ncos(2*n*Pi/3)+sin(2*n*Pi/3)/sqrt(3): seq(A047249(n), n=1..100); # Wesley Ivan Hurt, Jun 10 2016


MATHEMATICA

Select[Range[150], MemberQ[{3, 4, 5}, Mod[#, 6]]&] (* Harvey P. Dale, Nov 21 2012 *)


PROG

(MAGMA) [n : n in [0..150]  n mod 6 in [3..5]]; // Wesley Ivan Hurt, Jun 10 2016


CROSSREFS

Sequence in context: A285161 A329781 A139531 * A327257 A228941 A236211
Adjacent sequences: A047246 A047247 A047248 * A047250 A047251 A047252


KEYWORD

nonn,easy


AUTHOR

N. J. A. Sloane


STATUS

approved



