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A293751
Values of positive integer i such that floor(tan(-i)) = 1.
11
18, 21, 40, 43, 62, 65, 84, 87, 90, 106, 109, 112, 128, 131, 134, 150, 153, 156, 172, 175, 178, 197, 200, 219, 222, 241, 244, 263, 266, 285, 288, 307, 310, 329, 332, 351, 354, 373, 376, 395, 398, 417, 420, 439, 442, 445, 461, 464, 467, 483, 486, 489, 505, 508, 511, 527, 530, 533, 552, 555, 574, 577, 596
OFFSET
1,1
LINKS
FORMULA
floor(tan(-n)) = -ceiling(tan(n)).
MATHEMATICA
rootsn = Flatten[Position[Table[Floor[Tan[-i]], {i, 1, 10^3}], 1]];
(*a(n) = rootsn[[n]]*)
Select[Range@600, Floor@Tan@-# == 1 &] (* Robert G. Wilson v, Nov 19 2017 *)
PROG
(PARI) isok(n) = floor(tan(-n)) == 1; \\ Michel Marcus, Nov 03 2017
CROSSREFS
Cf. A000530, A293698, A293699, A293702, A293705, A293700, A293701, A293704. a(n) are also the roots of A195910(i)=1, starting from i=1.
Sequence in context: A244603 A377163 A120416 * A090891 A303298 A358592
KEYWORD
nonn
AUTHOR
V.J. Pohjola, Oct 15 2017
STATUS
approved