A246409 Nonnegative integers k satisfying sec(k) < sec(k+1) < sec(k+2) > sec(k+3).

33, 77, 121, 165, 188, 232, 276, 320, 366, 410, 454, 498, 565, 609, 653, 697, 743, 787, 831, 875, 898, 942, 986, 1030, 1076, 1120, 1164, 1208, 1275, 1319, 1363, 1407, 1453, 1497, 1541, 1585, 1608, 1652, 1696, 1740, 1786, 1830, 1874, 1918, 1985, 2029, 2073

Offset

1,1

Comments

A246407, A246408, and A246409 partition the nonnegative integers.

Links

Clark Kimberling, Table of n, a(n) for n = 1..1000

Mathematica

z = 500; f[x_] := f[x] = Sec[x];
Select[Range[0, z], f[#] > f[# + 1] &]  (* A246407 *)
Select[Range[0, z], f[#] < f[# + 1] > f[# + 2] &]  (* A246408 *)
Select[Range[0, z], f[#] < f[# + 1] < f[# + 2] > f[# + 3] &]  (* A246409 *)

Crossrefs

Cf. A246407, A246408.

Sequence in context: A134037 A138841 A248979 * A378481 A211837 A138863

Adjacent sequences: A246406 A246407 A246408 * A246410 A246411 A246412

Keyword

nonn,easy

Author

Clark Kimberling, Aug 25 2014

Status

approved