A036408 a(n) = ceiling(n^2/10).

0, 1, 1, 1, 2, 3, 4, 5, 7, 9, 10, 13, 15, 17, 20, 23, 26, 29, 33, 37, 40, 45, 49, 53, 58, 63, 68, 73, 79, 85, 90, 97, 103, 109, 116, 123, 130, 137, 145, 153, 160, 169, 177, 185, 194, 203, 212, 221, 231, 241, 250, 261, 271, 281, 292, 303, 314, 325

Offset: 0

Author

N. J. A. Sloane

Keywords

• nonn

Examples

			a(6) = ceiling(6^2/10) = ceiling(3.6) = 4.
		

Links

• Index entries for linear recurrences with constant coefficients, signature (2, -1, 0, 0, 0, 0, 0, 0, 0, 1, -2, 1).

Programs

Maple

A036408:=n->ceil(n^2/10); seq(A036408(k), k=0..100); # Wesley Ivan Hurt, Nov 06 2013

Mathematica

Table[Ceiling[n^2/10], {n,0,100}] (* Wesley Ivan Hurt, Nov 06 2013 *)
LinearRecurrence[{2,-1,0,0,0,0,0,0,0,1,-2,1},{0,1,1,1,2,3,4,5,7,9,10,13},60] (* Harvey P. Dale, Sep 27 2016 *)

Formula

From R. J. Mathar, Jan 22 2011: (Start)

a(n) = 2*a(n-1) - a(n-2) + a(n-10) - 2*a(n-11) + a(n-12).

G.f.: -x*(1 - x + x^7 - x^9 + x^10 + x^3) / ( (1+x)*(x^4 + x^3 + x^2 + x + 1)*(x^4 - x^3 + x^2 - x + 1)*(x-1)^3 ). (End)