A159357 - OEIS

A159357

Number of n X n arrays of squares of integers with every (n-2)X(n-2) subblock summing to 4

%I #8 Dec 18 2015 18:17:19

%S 13,3223,120420,1313859,7979037,34212213,116257928,334277285,

%T 847224269,1945263907,4124812588,8191927383,15400417725,27631699329,

%U 47624056752,79259627513,127918067213,200906501615,307976018164,461935595947

%N Number of n X n arrays of squares of integers with every (n-2)X(n-2) subblock summing to 4

%H R. H. Hardin, <a href="/A159357/b159357.txt">Table of n, a(n) for n=4..30</a>

%F Empirical G.f.: -17*x^3 - x^3*(17 - 140*x + 3718*x^2 + 90453*x^3 + 347157*x^4 + 218190*x^5 - 9588*x^6 - 3511*x^7 + 224*x^8)/(-1+x)^9. - _Vaclav Kotesovec_, Nov 30 2012

%K nonn

%O 4,1

%A _R. H. Hardin_ Apr 11 2009