A184017 n-1+ceiling((n/3)^2); complement of A184016.

1, 2, 3, 5, 7, 9, 12, 15, 17, 21, 24, 27, 31, 35, 39, 44, 49, 53, 59, 64, 69, 75, 81, 87, 94, 101, 107, 115, 122, 129, 137, 145, 153, 162, 171, 179, 189, 198, 207, 217, 227, 237, 248, 259, 269, 281, 292, 303, 315, 327, 339, 352, 365, 377, 391, 404, 417, 431, 445, 459, 474, 489, 503, 519, 534, 549, 565, 581, 597, 614, 631, 647, 665, 682, 699, 717, 735, 753, 772, 791

Offset

1,2

Links

Table of n, a(n) for n=1..80.

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

Formula

G.f.: x*(x^2+1)*(x^8-x^7+x^5-x^4-x^3+x^2-1)/((x-1)^3*(x^2+x+1)*(x^6+x^3+1)). [Colin Barker, Sep 23 2012]

Mathematica

a=9; b=0;
Table[n+Floor[(a*n+b)^(1/2)], {n, 100}]
Table[n-1+Ceiling[(n*n-b)/a], {n, 80}]

Crossrefs

Sequence in context: A348623 A200049 A279984 * A024195 A071423 A211004

Adjacent sequences: A184014 A184015 A184016 * A184018 A184019 A184020

Keyword

nonn,easy

Author

Clark Kimberling, Jan 09 2011

Status

approved