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a(n) = floor( 3*n/2 ) + floor( 2*n/3 ).
1

%I #12 Sep 06 2022 14:55:52

%S 0,1,4,6,8,10,13,14,17,19,21,23,26,27,30,32,34,36,39,40,43,45,47,49,

%T 52,53,56,58,60,62,65,66,69,71,73,75,78,79,82,84,86,88,91,92,95,97,99,

%U 101,104,105,108,110,112,114,117,118,121,123,125,127,130,131,134,136,138

%N a(n) = floor( 3*n/2 ) + floor( 2*n/3 ).

%H <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (0,1,1,0,-1).

%F G.f.: x*(1 + 4*x + 5*x^2 + 3*x^3)/((1 - x)^2*(1 + 2*x + 2*x^2 + x^3)). - _Bruno Berselli_, Jun 30 2014

%F a(n) = 2*n - 1 + floor(n/2) - floor((n-1)/3). - _Bruno Berselli_, Jun 15 2016

%t Table[Floor[3 n/2] + Floor[2 n/3], {n, 0, 70}] (* _Bruno Berselli_, Jun 30 2014 *)

%t LinearRecurrence[{0,1,1,0,-1},{0,1,4,6,8},80] (* _Harvey P. Dale_, Sep 06 2022 *)

%Y Cf. A090168.

%K nonn,easy

%O 0,3

%A _Clark Kimberling_, Nov 23 2003