A094154 - OEIS

The OEIS is supported by the many generous donors to the OEIS Foundation.

A094154

Bisection of A000939.

1, 4, 54, 2246, 164950, 18423144, 2905943328, 615376173184, 168483518571798, 57926238289970076, 24434798429947993054, 12408968034664788792008, 7468360391233437715595634, 5256695596753687250025931048, 4278271932454694494134007741950, 3986830862631720154048770746485900

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

LINKS

Table of n, a(n) for n=1..16.

S. W. Golomb and L. R. Welch, On the enumeration of polygons, Amer. Math. Monthly, 67 (1960), 349-353.

FORMULA

See Maple line.

MAPLE

with(numtheory); f:=proc(n) local t1, d; t1:=0; for d from 1 to n do if n mod d = 0 then t1:=t1+phi(n/d)^2*d!*(n/d)^d; fi; od: t1/(2*n^2); end;

CROSSREFS

Cf. A000939, A094155.