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A246405
Nonnegative integers k satisfying sec(k) > sec(k+1) < sec(k+2).
3
1, 3, 5, 7, 9, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 76, 79, 81, 83, 85, 87, 89, 91, 93, 95, 97, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 123, 125, 127, 129
OFFSET
1,2
COMMENTS
A246404, A246405, and A246406 partition the nonnegative integers.
LINKS
MATHEMATICA
z = 500; f[x_] := f[x] = Sec[x];
Select[Range[0, z], f[#] < f[# + 1] &] (* A246404 *)
Select[Range[0, z], f[#] > f[# + 1] < f[# + 2] &] (* A246405 *)
Select[Range[0, z], f[#] > f[# + 1] > f[# + 2] < f[# + 3] &] (* A246406 *)
CROSSREFS
Sequence in context: A191749 A038663 A291154 * A190328 A248106 A033036
KEYWORD
nonn,easy
AUTHOR
Clark Kimberling, Aug 25 2014
STATUS
approved