A121349 a(n) = round(Pi*2^(n-1)) for n >= 1, a(0) = 1.

1, 3, 6, 13, 25, 50, 101, 201, 402, 804, 1608, 3217, 6434, 12868, 25736, 51472, 102944, 205887, 411775, 823550, 1647099, 3294199, 6588397, 13176795, 26353589, 52707179, 105414357, 210828714, 421657428, 843314857, 1686629713, 3373259426

Offset

0,2

Comments

As n approaches infinity, the distance between the center and each vertex of a regular polygon with a(n) sides of unit length approaches 2^(n-2) units. - Ahmad J. Masad, Jul 02 2021

Links

Table of n, a(n) for n=0..31.

Mathematica

Table[FromDigits[RealDigits[Pi, 2, k][[1]], 2], {k, 1, 50}]

Prog

(PARI) a(n) = if(n<1, 1, round(Pi*2^(n-1))); \\ Michel Marcus, Jul 02 2021

Crossrefs

Cf. A004601, A068425, A155996, A293342.

Sequence in context: A005406 A005407 A005116 * A215984 A074890 A244704

Adjacent sequences: A121346 A121347 A121348 * A121350 A121351 A121352

Keyword

nonn,easy,less

Author

Carlos Alves, Jul 22 2006

Extensions

Better definition from Jon E. Schoenfield, Jan 17 2015

Definition amended by Georg Fischer, Aug 31 2021

Status

approved