login
1/4 the number of n X n arrays of squares of integers with every 2X2 subblock summing to 27
0

%I #4 Dec 18 2015 18:17:19

%S 7,22,45,103,193,421,777,1681,3097,6697,12345,26713,49273,106681,

%T 196857,426361,786937,1704697,3146745,6817273,12584953,27266041,

%U 50335737,109058041,201334777,436219897

%N 1/4 the number of n X n arrays of squares of integers with every 2X2 subblock summing to 27

%F Conjecture: G.f.: x^2*(-7-8*x^4+32*x^3+19*x^2-15*x)/((x-1)*(2*x+1)*(2*x-1)*(2*x^2-1)) [From Maksym Voznyy (voznyy(AT)mail.ru), Jul 26 2009]

%K nonn

%O 2,1

%A _R. H. Hardin_ Apr 06 2009