A122772 Numbers k, excluding powers of 2, such that a regular k-sided polygon can be constructed with a ruler and compass.

3, 5, 6, 10, 12, 15, 17, 20, 24, 30, 34, 40, 48, 51, 60, 68, 80, 85, 96, 102, 120, 136, 160, 170, 192, 204, 240, 255, 257, 272, 320, 340, 384, 408, 480, 510, 514, 544, 640, 680, 768, 771, 816, 960, 1020, 1028, 1088, 1280, 1285, 1360, 1536, 1542, 1632, 1920, 2040

Offset

1,1

Comments

Sequence A003401 with powers of 2 deleted.

Links

Table of n, a(n) for n=1..55.

Eric Weisstein's World of Mathematics, Fermat Prime.

Crossrefs

See A003401, which is the main entry for this problem.

Sequence in context: A047327 A028927 A099190 * A140449 A207063 A359584

Adjacent sequences: A122769 A122770 A122771 * A122773 A122774 A122775

Keyword

nonn

Author

Alexander Adamchuk, Oct 29 2006, revised Nov 07 2006

Status

approved