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A140276 Floor of the (first-quadrant) angle in degrees whose tangent is n. 2
0, 45, 63, 71, 75, 78, 80, 81, 82, 83, 84, 84, 85, 85, 85, 86, 86, 86, 86, 86, 87, 87, 87, 87, 87, 87, 87, 87, 87, 88, 88, 88, 88, 88, 88, 88, 88, 88, 88, 88, 88, 88, 88, 88, 88, 88, 88, 88, 88, 88, 88, 88, 88, 88, 88, 88, 88, 88, 89, 89, 89, 89, 89, 89, 89, 89, 89, 89, 89, 89 (list; graph; refs; listen; history; internal format)
OFFSET

0,2

COMMENTS

180*atan(n)/Pi is an exact integer only for n = 0 and n = 1 (and n = -1). a(n) = 89 for n >= 58.

FORMULA

For all integers n, a(n) = floor(180*atan(n)/Pi) = -A140278(-n), where a negative term represents a fourth-quadrant angle. Terms shown are only for n >= 0.

EXAMPLE

a(1) = 45 degrees as that is the first-quadrant angle with tan(45 deg) = 1. a(2) = 63 degrees as 180*atan(2)/Pi = 63.4349... and floor(63.4349...) = 63.

PROG

(PARI) a(n) = floor(180*atan(n)/Pi)

CROSSREFS

Cf. A140277, A140278.

Sequence in context: A151743 A179007 A138046 * A140277 A077646 A175761

Adjacent sequences:  A140273 A140274 A140275 * A140277 A140278 A140279

KEYWORD

nonn

AUTHOR

Rick L. Shepherd (rshepherd2(AT)hotmail.com), May 16 2008

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Last modified February 15 14:02 EST 2012. Contains 205811 sequences.