A187336 Sum{floor(kn/6), k=1,2,3,4,5}.

0, 0, 3, 6, 8, 10, 15, 15, 18, 21, 23, 25, 30, 30, 33, 36, 38, 40, 45, 45, 48, 51, 53, 55, 60, 60, 63, 66, 68, 70, 75, 75, 78, 81, 83, 85, 90, 90, 93, 96, 98, 100, 105, 105, 108, 111, 113, 115, 120, 120, 123, 126, 128, 130, 135, 135, 138, 141, 143, 145, 150, 150, 153, 156, 158, 160, 165, 165, 168, 171, 173, 175, 180, 180, 183, 186, 188, 190, 195, 195, 198, 201, 203, 205, 210, 210, 213, 216, 218, 220, 225, 225, 228, 231, 233, 235, 240, 240, 243, 246, 248, 250, 255, 255, 258, 261, 263, 265, 270, 270

Offset: 0

Author

Clark Kimberling, Mar 08 2011

Keywords

• nonn

Programs

Mathematica

Table[Sum[Floor[k*n/6], {k,1,5}],{n,0,200}]

Formula

a(n)=Sum{floor(kn/6), k=1,2,3,4,5}.

Empirical g.f.: x^2*(5*x^4+2*x^3+2*x^2+3*x+3) / ((x-1)^2*(x+1)*(x^2-x+1)*(x^2+x+1)). - Colin Barker, Mar 20 2013