id:A140278 - OEIS Search Results

Search: id:A140278

Displaying 1-1 of 1 results found.

page 1

Ceiling of the (first-quadrant) angle in degrees whose tangent is n.

+0
3

0, 45, 64, 72, 76, 79, 81, 82, 83, 84, 85, 85, 86, 86, 86, 87, 87, 87, 87, 87, 88, 88, 88, 88, 88, 88, 88, 88, 88, 89, 89, 89, 89, 89, 89, 89, 89, 89, 89, 89, 89, 89, 89, 89, 89, 89, 89, 89, 89, 89, 89, 89, 89, 89, 89, 89, 89, 89, 90, 90, 90, 90, 90, 90, 90, 90, 90, 90, 90, 90 (list; graph; listen)

	OFFSET	`0,2`
	COMMENT	`180*atan(n)/Pi is an exact integer only for n = 0 and n = 1 (and n = -1). a(n) = 90 for n >= 58.`
	FORMULA	`For all integers n, a(n) = ceil(180*atan(n)/Pi) = -A140276(-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) = 64 degrees as 180*atan(2)/Pi = 63.4349... and ceil(63.4349...) = 64.`
	PROGRAM	`(PARI) a(n) = ceil(180*atan(n)/Pi)`
	CROSSREFS	`Cf. A140276, A140277.` `Sequence in context: A077646 A046364 A051773 this_sequence A046426 A056776 A038494` `Adjacent sequences: A140275 A140276 A140277 this_sequence A140279 A140280 A140281`
	KEYWORD	`nonn`
	AUTHOR	`Rick L. Shepherd (rshepherd2(AT)hotmail.com), May 17 2008`

page 1

Search completed in 0.002 seconds

Last modified December 4 23:11 EST 2009. Contains 170347 sequences.

AT&T Labs Research