A246407 Nonnegative integers k satisfying sec(k) > sec(k+1).

1, 3, 5, 7, 9, 11, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53, 55, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 76, 79, 81, 83, 85, 87, 89, 91, 93, 95, 97, 99, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 123, 125

Offset

1,2

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 *)
Position[Partition[Sec[Range[150]], 2, 1], _?(#[[1]]>#[[2]]&), {1}, Heads-> False]//Flatten (* Harvey P. Dale, Apr 26 2016 *)

Crossrefs

Cf. A246408, A246409, A246404 (complement of A246407).

Sequence in context: A276384 A329827 A182765 * A151916 A187687 A056617

Adjacent sequences: A246404 A246405 A246406 * A246408 A246409 A246410

Keyword

nonn,easy

Author

Clark Kimberling, Aug 25 2014

Status

approved