A252521 - OEIS

%I #6 Apr 25 2023 13:21:46

%S 1471,5214,21510,47308,268555,1215491,2662952,15755867,73792188,

%T 160605830,977103095,4668722734,10119572634,62609075589,302574704284,

%U 654293895244,4086229186201,19870347822346,42913053749386

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

%C Column 6 of A252523.

%H R. H. Hardin, <a href="/A252521/b252521.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 123*a(n-3) -4692*a(n-6) +69418*a(n-9) -496012*a(n-12) +1948488*a(n-15) -4564660*a(n-18) +6732956*a(n-21) -6502868*a(n-24) +4253029*a(n-27) -1930703*a(n-30) +601744*a(n-33) -118886*a(n-36) +12592*a(n-39) -528*a(n-42) for n>50.

%e Some solutions for n=4

%e ..3..3..2..3..0..2..3..3....3..2..3..3..2..3..3..2....3..2..3..3..2..3..3..2

%e ..0..3..2..3..3..2..0..3....2..1..2..2..1..2..2..1....2..1..2..2..1..2..2..1

%e ..2..2..1..2..2..1..2..2....3..2..0..3..2..3..3..2....3..2..3..3..2..3..3..2

%e ..3..3..2..0..3..2..3..3....3..2..3..3..2..3..3..2....3..2..3..0..2..3..3..2

%e ..3..3..2..3..3..2..3..3....2..1..2..2..1..2..2..1....2..1..2..2..1..2..2..1

%e ..2..2..1..2..2..1..2..2....3..2..3..0..2..3..3..2....3..2..0..3..2..3..0..2

%Y Cf. A252523.

%K nonn

%O 1,1

%A _R. H. Hardin_, Dec 18 2014