A342533 a(n) is the number of n-gons in A000940 that display symmetry (reflection / rotation).

1, 2, 4, 11, 24, 81, 193, 772, 1920, 8735, 23040

Offset

3,2

Links

Table of n, a(n) for n=3..13.

Formula

a(p) = (2^((p-1)/2)*((p-1)/2)!)/2 for prime p.

Example

Of the A000940(6)=12 hexagons, 11 have symmetry and 1 is asymmetric, so a(6)=11.

Crossrefs

Cf. A000940.

Sequence in context: A230984 A196195 A205500 * A131434 A100550 A329707

Adjacent sequences: A342530 A342531 A342532 * A342534 A342535 A342536

Keyword

nonn,more

Author

Ian Mooney, Mar 14 2021

Status

approved