cp's OEIS Frontend

A252570 Number of (n+2)X(4+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 1 2 5 6 or 7 and every 3X3 column and antidiagonal sum not equal to 1 2 5 6 or 7.

%I A252570 #6 Jun 02 2025 11:23:23
%S A252570 1694,3441,9051,25882,88844,263046,802760,2655311,7860183,24273030,
%T A252570 79767276,236117012,730342433,2398390660,7098703610,21963448780,
%U A252570 72127785139,213445574577,660482900457,2169282202310,6418274172794
%N A252570 Number of (n+2)X(4+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 1 2 5 6 or 7 and every 3X3 column and antidiagonal sum not equal to 1 2 5 6 or 7.
%C A252570 Column 4 of A252574
%H A252570 R. H. Hardin, <a href="/A252570/b252570.txt">Table of n, a(n) for n = 1..210</a>
%F A252570 Empirical: a(n) = 82*a(n-3) -2429*a(n-6) +33486*a(n-9) -261118*a(n-12) +1295078*a(n-15) -4396152*a(n-18) +10604184*a(n-21) -18276440*a(n-24) +22254797*a(n-27) -19021565*a(n-30) +11461650*a(n-33) -4926134*a(n-36) +1526628*a(n-39) -338818*a(n-42) +51264*a(n-45) -4731*a(n-48) +223*a(n-51) -4*a(n-54) for n>60
%e A252570 Some solutions for n=4
%e A252570 ..3..2..2..3..2..2....2..0..0..2..0..0....1..0..1..1..0..0....0..2..0..0..2..0
%e A252570 ..0..2..0..0..2..0....0..1..0..0..2..0....0..1..0..0..2..0....2..2..3..1..2..3
%e A252570 ..0..0..1..0..0..1....2..2..3..2..2..3....2..2..3..2..1..3....1..0..0..2..0..0
%e A252570 ..3..2..2..3..2..2....1..0..0..1..0..0....2..0..0..2..0..0....0..2..0..0..2..0
%e A252570 ..0..1..0..0..2..0....0..1..0..0..1..0....0..2..0..0..2..0....2..1..3..1..2..3
%e A252570 ..0..0..2..0..0..1....2..2..3..2..2..3....1..1..3..1..2..3....2..0..0..2..0..0
%K A252570 nonn
%O A252570 1,1
%A A252570 _R. H. Hardin_, Dec 18 2014