A252617 - OEIS

%I #6 May 27 2021 15:02:06

%S 725,1379,2815,6019,13879,31514,71856,170404,401865,928144,2224005,

%T 5295937,12290495,29585255,70665020,164351400,396380374,947723031,

%U 2206641736,5326057859,12737364595,29676414147,71648092677,171334763922

%N Number of (2+2) X (n+2) 0..3 arrays with every 3 X 3 subblock row and diagonal sum equal to 0 3 5 6 or 8 and every 3 X 3 column and antidiagonal sum not equal to 0 3 5 6 or 8.

%C Row 2 of A252615.

%H R. H. Hardin, <a href="/A252617/b252617.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = a(n-1) +48*a(n-3) -48*a(n-4) -939*a(n-6) +939*a(n-7) +9891*a(n-9) -9891*a(n-10) -63231*a(n-12) +63231*a(n-13) +263827*a(n-15) -263827*a(n-16) -759379*a(n-18) +759379*a(n-19) +1583561*a(n-21) -1583561*a(n-22) -2493304*a(n-24) +2493304*a(n-25) +3037897*a(n-27) -3037897*a(n-28) -2885834*a(n-30) +2885834*a(n-31) +2133236*a(n-33) -2133236*a(n-34) -1202312*a(n-36) +1202312*a(n-37) +495108*a(n-39) -495108*a(n-40) -137768*a(n-42) +137768*a(n-43) +20352*a(n-45) -20352*a(n-46) -1152*a(n-48) +1152*a(n-49) for n>52.

%e Some solutions for n=4

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

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

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

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

%Y Cf. A252615.

%K nonn

%O 1,1

%A _R. H. Hardin_, Dec 19 2014