A061004 Nearest integer to n^6/36.

0, 2, 20, 114, 434, 1296, 3268, 7282, 14762, 27778, 49210, 82944, 134078, 209154, 316406, 466034, 670488, 944784, 1306830, 1777778, 2382392, 3149442, 4112108, 5308416, 6781684, 8580994, 10761680, 13385842, 16522870, 20250000, 24652880

Offset

1,2

Links

Table of n, a(n) for n=1..31.

Index entries for linear recurrences with constant coefficients, signature (5,-9,6,0,0,0,-6,9,-5,1).

Formula

G.f.: -2*x^2*(x^6+5*x^5+16*x^4+16*x^3+16*x^2+5*x+1)/((x-1)^7*(x+1)*(x^2+x+1)). [Colin Barker, Sep 18 2012]

Mathematica

ni[n_]:=Module[{c=n^6/36}, If[Ceiling[c]-c<c-Floor[c], Ceiling[c], Floor[ c]]]; Array[ni, 40] (* Harvey P. Dale, Oct 14 2012 *)

Crossrefs

Sequence in context: A001797 A084894 A203238 * A278772 A213432 A219837

Adjacent sequences: A061001 A061002 A061003 * A061005 A061006 A061007

Keyword

nonn,easy

Author

N. J. A. Sloane, May 15 2001

Status

approved