OFFSET
1,3
COMMENTS
This is the number of cells in a 1/(2*n)-th sector of a regular (2*n)-gon with all diagonals drawn. See Rubinstein's illustrations in A007678.
LINKS
Scott R. Shannon, Table of n, a(n) for n = 1..71
EXAMPLE
CROSSREFS
KEYWORD
nonn
AUTHOR
Scott R. Shannon and N. J. A. Sloane, Mar 07 2021
STATUS
approved