A184632 Floor(1/{(8+n^4)^(1/4)}), where {}=fractional part.

1, 4, 13, 32, 62, 108, 171, 256, 364, 500, 665, 864, 1098, 1372, 1687, 2048, 2456, 2916, 3429, 4000, 4630, 5324, 6083, 6912, 7812, 8788, 9841, 10976, 12194, 13500, 14895, 16384, 17968, 19652, 21437, 23328, 25326, 27436, 29659, 32000, 34460, 37044, 39753, 42592, 45562, 48668, 51911, 55296, 58824, 62500, 66325, 70304, 74438, 78732, 83187, 87808, 92596, 97556, 102689, 108000

Offset

1,2

Links

Table of n, a(n) for n=1..60.

Index entries for linear recurrences with constant coefficients, signature (3, -2, -2, 3, -1).

Formula

a(n)=floor(1/{(8+n^4)^(1/4)}), where {}=fractional part.

It appears that a(n)=3a(n-1)-2a(n-2)-2a(n-3)+3a(n-4)-a(n-5) for n>=7.

Mathematica

p[n_]:=FractionalPart[(n^4+8)^(1/4)];
q[n_]:=Floor[1/p[n]];
Table[q[n], {n, 1, 80}]
FindLinearRecurrence[Table[q[n], {n, 1, 1000}]]
Join[{1}, LinearRecurrence[{3, -2, -2, 3, -1}, {4, 13, 32, 62, 108}, 59]] (* Ray Chandler, Aug 02 2015 *)

Crossrefs

Cf. A184536, A036487.

Sequence in context: A270976 A272510 A036487 * A212747 A011936 A037235

Adjacent sequences: A184629 A184630 A184631 * A184633 A184634 A184635

Keyword

nonn

Author

Clark Kimberling, Jan 18 2011

Status

approved