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A332488
a(n) = least positive integer k such that sin(n*k)*sin(n*k + k) < 0.
2
3, 1, 1, 1, 2, 11, 4, 1, 1, 1, 2, 5, 7, 2, 1, 1, 1, 3, 20, 2, 1, 1, 1, 2, 23, 3, 1, 1, 1, 2, 7, 5, 1, 1, 1, 1, 4, 10, 2, 1, 1, 1, 3, 177, 3, 1, 1, 1, 2, 11, 4, 1, 1, 1, 2, 5, 6, 2, 1, 1, 1, 3, 18, 2, 1, 1, 1, 2, 27, 3, 1, 1, 1, 2, 7, 5, 1, 1, 1, 1, 4, 9, 2
OFFSET
1,1
COMMENTS
a(n) = least positive integer k such that sin(n*k) and sin(n*k + k) have opposite signs.
EXAMPLE
The signs of sin(6), sin(12), sin(18), ..., sin(72) are indicated by - - - - - - - - - - - + ; that's eleven -'s followed by +, so that a(6) = 11.
MATHEMATICA
Table[First[Map[Length, Split[Table[Sign[Sin[k n]], {k, 1, 500}]]]], {n, 1, 100}]
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Clark Kimberling, Apr 21 2020
STATUS
approved