This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A094154 #6 Oct 01 2017 03:01:53 %S A094154 1,4,54,2246,164950,18423144,2905943328,615376173184,168483518571798, %T A094154 57926238289970076,24434798429947993054,12408968034664788792008, %U A094154 7468360391233437715595634,5256695596753687250025931048,4278271932454694494134007741950,3986830862631720154048770746485900 %N A094154 Bisection of A000939. %H A094154 S. W. Golomb and L. R. Welch, <a href="http://www.jstor.org/stable/2308978">On the enumeration of polygons</a>, Amer. Math. Monthly, 67 (1960), 349-353. %F A094154 See Maple line. %p A094154 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; %Y A094154 Cf. A000939, A094155. %K A094154 nonn %O A094154 1,2 %A A094154 _N. J. A. Sloane_, May 05 2004