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A246406
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Nonnegative integers k satisfying sec(k) > sec(k+1) > sec(k+2) < sec(k+3).
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3
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11, 55, 99, 143, 210, 254, 298, 342, 388, 432, 476, 520, 543, 587, 631, 675, 721, 765, 809, 853, 920, 964, 1008, 1052, 1098, 1142, 1186, 1230, 1253, 1297, 1341, 1385, 1431, 1475, 1519, 1563, 1630, 1674, 1718, 1762, 1808, 1852, 1896, 1940, 1963, 2007, 2051
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OFFSET
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1,1
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COMMENTS
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LINKS
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MATHEMATICA
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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 *)
Position[Partition[Sec[Range[2100]], 4, 1], _?(#[[1]]>#[[2]]>#[[3]]< #[[4]]&), 1, Heads->False]//Flatten (* Harvey P. Dale, Mar 10 2019 *)
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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STATUS
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approved
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