A184109 n + ceiling(n^2/9); complement of A184108.

2, 3, 4, 6, 8, 10, 13, 16, 18, 22, 25, 28, 32, 36, 40, 45, 50, 54, 60, 65, 70, 76, 82, 88, 95, 102, 108, 116, 123, 130, 138, 146, 154, 163, 172, 180, 190, 199, 208, 218, 228, 238, 249, 260, 270, 282, 293, 304, 316, 328, 340, 353, 366, 378, 392, 405, 418, 432, 446, 460, 475, 490, 504, 520, 535, 550, 566, 582, 598, 615, 632, 648, 666, 683, 700, 718, 736, 754, 773, 792, 810, 830, 849, 868, 888, 908, 928, 949, 970, 990

Offset

1,1

Links

Matthew House, Table of n, a(n) for n = 1..10000

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

Formula

G.f.: (2*x-x^2+x^4+x^7-x^9)/(1-2*x+x^2-x^9+2*x^10-x^11). - Matthew House, Feb 15 2017

a(n) = +2 a(n-1) -a(n-2) +a(n-9) -2 a(n-10) +a(n-11). - R. J. Mathar, Mar 11 2012

Mathematica

a=9; b=-9;
Table[n+Floor[(a*n+b)^(1/2)], {n, 100}]
Table[n-1+Ceiling[(n^2-b)/a], {n, 90}]
Table[n+Ceiling[n^2/9], {n, 100}] (* or *) LinearRecurrence[{2, -1, 0, 0, 0, 0, 0, 0, 1, -2, 1}, {2, 3, 4, 6, 8, 10, 13, 16, 18, 22, 25}, 100] (* Harvey P. Dale, Jun 25 2021 *)

Prog

(PARI) a(n)=a(n)=(n^2+9*n+8)\9 \\ Charles R Greathouse IV, Feb 15 2017

Crossrefs

Complement of A184108.

Sequence in context: A352929 A096061 A100919 * A214780 A024174 A008739

Adjacent sequences: A184106 A184107 A184108 * A184110 A184111 A184112

Keyword

nonn,easy

Author

Clark Kimberling, Jan 09 2011

Status

approved