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A246409
Nonnegative integers k satisfying sec(k) < sec(k+1) < sec(k+2) > sec(k+3).
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
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
Sequence in context: A134037 A138841 A248979 * A211837 A138863 A138866
KEYWORD
nonn,easy
AUTHOR
Clark Kimberling, Aug 25 2014
STATUS
approved