OFFSET
0,3
LINKS
T. Pisanski, D. Schattschneider and B. Servatius, Applying Burnside's lemma to a one-dimensional Escher problem, Math. Mag., 79 (2006), 167-180. See G(n).
FORMULA
See Maple program.
MAPLE
V:=proc(n) local k, t1; t1:=0; for k in divisors(n) do t1 := t1+phi(k)*4^(n/k); od: t1; end;
H:=n-> if n mod 2 = 0 then (n/2)*4^(n/2); else 0; fi;
R:=proc(n) local k, t1; t1:=0; for k in divisors(n) do if k mod 2 = 0 then t1 := t1+phi(k)*4^(n/k); fi; od: t1; end;
A123046:=n->(V(n)+2*H(n)+R(n))/(4*n);
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Nov 11 2006
STATUS
approved