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A134030 Areas of regular n-sided polygons with length of each side equal to 1 (rounded). 1
1, 2, 3, 4, 5, 6, 8, 9, 11, 13, 15, 18, 20, 23, 26, 28, 32, 35, 38, 42, 46, 49, 54, 58, 62, 67, 71, 76, 81, 86, 92, 97, 103, 109, 115, 121, 127, 134, 140, 147, 154, 161, 168, 176, 183, 191, 199, 207, 215, 223, 232, 240, 249, 258, 267, 277, 286 (list; graph; refs; listen; history; text; internal format)
OFFSET

4,2

LINKS

Table of n, a(n) for n=4..60.

Wikipedia, Regular polygons

Kival Ngaokrajang, Illustration of initial terms

FORMULA

a(n) = Round(n/(4*tan(Pi/n)).

EXAMPLE

a(5) = 5 because a(1) is a square and a(5) is a regular octagon with sides equal to 1 which has a rounded area of 5.

PROG

(PARI) a(n) = round(n / (4*tan(Pi/n))); \\ Michel Marcus, Sep 04 2013

CROSSREFS

Sequence in context: A050418 A011869 A177738 * A226189 A235592 A100054

Adjacent sequences:  A134027 A134028 A134029 * A134031 A134032 A134033

KEYWORD

easy,nonn

AUTHOR

Ben Paul Thurston, Jan 11 2008

STATUS

approved

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Last modified April 14 09:23 EDT 2021. Contains 342948 sequences. (Running on oeis4.)