A248578 a(n) = round(1/(Pi-n*sin(Pi/n))).

0, 1, 2, 3, 5, 7, 10, 12, 16, 19, 24, 28, 33, 38, 44, 50, 56, 63, 70, 77, 85, 94, 102, 112, 121, 131, 141, 152, 163, 174, 186, 198, 211, 224, 237, 251, 265, 280, 294, 310, 325, 341, 358, 375, 392, 410, 428, 446, 465, 484

Offset: 1

Author

M. F. Hasler, Oct 08 2014

Keywords

• nonn

Comments

n*sin(Pi/n) is known as the Archimedean approximation to Pi, the present sequence measures [the reciprocal of] the error. See A248358 for the integer part.

Crossrefs

Cf. A248358, A248355.

Programs

Mathematica

Table[Round[1/(Pi -n Sin[Pi/n])],{n,50}] (* Harvey P. Dale, Jun 30 2022 *)

PARI

a(n)=round(1/(Pi-n*sin(Pi/n)))