A307454 a(n) is the number of canonical polygons with 2n edges having 2-fold rotational symmetry.

1, 3, 9, 33, 123, 513, 2077, 8759, 37184, 159508, 688446, 2993451, 13082724

Offset

2,2

Links

Table of n, a(n) for n=2..14.

Lars Blomberg, Examples of canonical polygons with 2-fold rotational symmetry

Crossrefs

Cf. A052436, A307387, A307391, A307426, A307454, A307455, A307456, A307519.

Sequence in context: A082841 A151038 A039648 * A219261 A182530 A049182

Adjacent sequences: A307451 A307452 A307453 * A307455 A307456 A307457

Keyword

nonn,more

Author

Lars Blomberg, Apr 09 2019

Status

approved