A202326 Number of regular polygons constructable by straightedge and compass up to 10^n.

5, 24, 52, 93, 145, 206, 280, 363, 456, 566, 670, 774, 886, 990, 1094, 1206, 1310, 1414, 1526, 1630, 1734, 1842, 1946, 2054, 2162, 2266, 2374, 2482, 2586, 2690, 2794, 2902, 3010, 3114, 3222, 3328, 3432, 3542, 3646, 3750, 3862, 3966, 4070, 4182, 4286, 4390

Offset

1,1

References

Albert H. Beiler, Recreations in the theory of numbers, New York, Dover, (2nd ed.) 1966, p. 182.

Links

Table of n, a(n) for n=1..46.

Example

a(1) = 5 since there are five regular polygons with number of sides not exceeding 10, i.e., the triangle, square, pentagon, hexagon, and octagon.

Crossrefs

Cf. A003401.

Sequence in context: A006145 A219509 A372455 * A085646 A121546 A135703

Adjacent sequences: A202323 A202324 A202325 * A202327 A202328 A202329

Keyword

nonn

Author

Martin Renner, Dec 16 2011

Status

approved