A049636 Congruent to 0 or 2 mod 3, but not equal to 0 or 3.

2, 5, 6, 8, 9, 11, 12, 14, 15, 17, 18, 20, 21, 23, 24, 26, 27, 29, 30, 32, 33, 35, 36, 38, 39, 41, 42, 44, 45, 47, 48, 50, 51, 53, 54, 56, 57, 59, 60, 62, 63, 65, 66, 68, 69, 71, 72, 74, 75, 77, 78, 80, 81, 83, 84, 86, 87, 89, 90, 92, 93, 95, 96, 98, 99, 101, 102, 104, 105, 107, 108

Offset: 0

Author

Clark Kimberling

Keywords

• nonn

Comments

a(n) = T(n, 2), array T as in A049627.

Links

• G. C. Greubel, Table of n, a(n) for n = 0..1000

Crossrefs

Cf. A007494.

Programs

Mathematica

Join[{2},Select[Range[4,100],MemberQ[{0,2},Mod[#,3]]&]] (* or *) With[{nn=100},Join[{2},Riffle[Range[5,nn,3],Range[6,nn,3]]]] (* Harvey P. Dale, Jul 14 2012 *)

PARI

x='x+O('x^20); Vec(-(x+2)*(x^2-x-1)/((1-x)^2*(1+x))) \\ G. C. Greubel, Dec 15 2017

Formula

O.g.f.: -(x+2)(x^2-x-1)/((1-x)^2*(1+x)). - R. J. Mathar, Aug 13 2008

Extensions

Terms a(38) onward added by G. C. Greubel, Dec 15 2017