This site is supported by donations to The OEIS Foundation.

Thanks to everyone who made a donation during our annual appeal!
To see the list of donors, or make a donation, see the OEIS Foundation home page.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A256853 Decimal expansion of area of a regular 9-gon with unit edge length. 8
 6, 1, 8, 1, 8, 2, 4, 1, 9, 3, 7, 7, 2, 9, 0, 0, 1, 2, 7, 2, 1, 3, 7, 4, 4, 0, 5, 9, 6, 1, 9, 7, 6, 3, 6, 1, 4, 9, 4, 1, 7, 1, 3, 3, 4, 8, 1, 3, 4, 3, 5, 8, 0, 9, 8, 3, 8, 6, 8, 6, 4, 2, 5, 5, 6, 6, 9, 7, 7, 1, 0, 7, 1, 2, 3, 3, 5, 8, 4, 6, 6, 4, 7, 6, 6, 3, 5, 9, 5, 5, 3, 3, 8, 9, 0, 7, 9, 1, 8, 4, 0, 9, 9, 0, 2 (list; constant; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Stanislav Sykora, Table of n, a(n) for n = 1..2000 Wikipedia, Nonagon Wikipedia, Regular polygon FORMULA Equals (p/4)*cot(Pi/p), with p = 9. EXAMPLE 6.181824193772900127213744059619763614941713348134358098386864... MATHEMATICA RealDigits[(9/4)*Cot[Pi/9], 10, 50][[1]] (* G. C. Greubel, Jul 03 2017 *) PROG (PARI) p=9; a=(p/4)*cotan(Pi/p)        \\ Use realprecision in excess CROSSREFS Cf. A000796, A019968, A120011 (p=3), A102771 (p=5), A104956 (p=6), A178817 (p=7), A090488 (p=8), A178816 (p=10), A256854 (p=11), A178809 (p=12). Sequence in context: A186099 A021622 A073228 * A258404 A244692 A248589 Adjacent sequences:  A256850 A256851 A256852 * A256854 A256855 A256856 KEYWORD nonn,cons AUTHOR Stanislav Sykora, Apr 12 2015 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified January 16 01:15 EST 2019. Contains 319184 sequences. (Running on oeis4.)