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A073518 Cotangent of Pi/prime(n), rounded to nearest integer. 0
0, 1, 1, 2, 3, 4, 5, 6, 7, 9, 10, 12, 13, 14, 15, 17, 19, 19, 21, 23, 23, 25, 26, 28, 31, 32, 33, 34, 35, 36, 40, 42, 44, 44, 47, 48, 50, 52, 53, 55, 57, 58, 61, 61, 63, 63, 67, 71, 72, 73, 74, 76, 77, 80, 82, 84, 86, 86, 88, 89, 90, 93, 98, 99, 100, 101, 105, 107, 110, 111, 112 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,4

LINKS

Table of n, a(n) for n=1..71.

FORMULA

a(n) = round(cotan(Pi/prime(n)) or a(n) = round(1/tan(Pi/prime(n)).

EXAMPLE

n=8: p(n)=19; cotan(Pi/19) = 5.9926... => 6.

MATHEMATICA

Table[Round[Cot[Pi/Prime[n]]], {n, 71}] (* Jayanta Basu, Jul 01 2013 *)

PROG

(PARI) a(n)=if(n>1, round(1/tan(Pi/prime(n))), 0) \\ Charles R Greathouse IV, Jul 01 2013

CROSSREFS

Sequence in context: A039163 A125299 A063949 * A144769 A165737 A033104

Adjacent sequences:  A073515 A073516 A073517 * A073519 A073520 A073521

KEYWORD

nonn

AUTHOR

Werner D. Sand, Aug 31 2002

STATUS

approved

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Last modified September 22 17:05 EDT 2018. Contains 315270 sequences. (Running on oeis4.)