cp's OEIS Frontend

A228506 T(n,k)=Number of nXk binary arrays with top left value 1 and no two ones adjacent horizontally, vertically, diagonally or antidiagonally.

%I A228506 #7 Sep 01 2013 17:48:59
%S A228506 1,1,1,2,1,2,3,3,3,3,5,5,12,5,5,8,11,29,29,11,8,13,21,88,87,88,21,13,
%T A228506 21,43,239,358,358,239,43,21,34,85,684,1252,2002,1252,684,85,34,55,
%U A228506 171,1909,4749,9528,9528,4749,1909,171,55,89,341,5392,17285,49101,59839,49101
%N A228506 T(n,k)=Number of nXk binary arrays with top left value 1 and no two ones adjacent horizontally, vertically, diagonally or antidiagonally.
%C A228506 Table starts
%C A228506 ..1...1....2.....3.......5........8........13.........21..........34
%C A228506 ..1...1....3.....5......11.......21........43.........85.........171
%C A228506 ..2...3...12....29......88......239.......684.......1909........5392
%C A228506 ..3...5...29....87.....358.....1252......4749......17285.......64235
%C A228506 ..5..11...88...358....2002.....9528.....49101.....243118.....1228036
%C A228506 ..8..21..239..1252....9528....59839....413786....2724191....18387032
%C A228506 .13..43..684..4749...49101...413786...3862849...34229311...311423874
%C A228506 .21..85.1909.17285..243118..2724191..34229311..405580157..4951454523
%C A228506 .34.171.5392.64235.1228036.18387032.311423874.4951454523.81304395949
%H A228506 R. H. Hardin, <a href="/A228506/b228506.txt">Table of n, a(n) for n = 1..1740</a>
%F A228506 Empirical for column k:
%F A228506 k=1: a(n) = a(n-1) +a(n-2)
%F A228506 k=2: a(n) = a(n-1) +2*a(n-2)
%F A228506 k=3: a(n) = 2*a(n-1) +3*a(n-2) -2*a(n-3)
%F A228506 k=4: a(n) = 2*a(n-1) +7*a(n-2) -2*a(n-3) -3*a(n-4)
%F A228506 k=5: a(n) = 2*a(n-1) +16*a(n-2) +a(n-3) -27*a(n-4) +a(n-5) +4*a(n-6)
%F A228506 k=6: [order 8]
%F A228506 k=7: [order 14]
%e A228506 Some solutions for n=4 k=4
%e A228506 ..1..0..0..0....1..0..0..0....1..0..0..1....1..0..0..0....1..0..0..1
%e A228506 ..0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0
%e A228506 ..0..0..0..0....1..0..0..0....0..0..0..0....0..0..0..1....1..0..0..0
%e A228506 ..1..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0....0..0..1..0
%Y A228506 Column 1 is A000045
%Y A228506 Column 2 is A001045
%K A228506 nonn,tabl
%O A228506 1,4
%A A228506 _R. H. Hardin_ Aug 23 2013