cp's OEIS Frontend

A208175 T(n,k)=Number of nXk 0..3 arrays with new values 0..3 introduced in row major order and no element equal to more than one of its immediate leftward or upward neighbors.

%I A208175 #7 Jul 22 2025 21:14:02
%S A208175 1,2,2,5,13,5,15,159,159,15,51,2277,8469,2277,51,187,33831,473928,
%T A208175 473928,33831,187,715,506493,26625693,99752346,26625693,506493,715,
%U A208175 2795,7594479,1496307201,21002874867,21002874867,1496307201,7594479,2795,11051
%N A208175 T(n,k)=Number of nXk 0..3 arrays with new values 0..3 introduced in row major order and no element equal to more than one of its immediate leftward or upward neighbors.
%C A208175 Table starts
%C A208175 ....1.........2.............5.................15.....................51
%C A208175 ....2........13...........159...............2277..................33831
%C A208175 ....5.......159..........8469.............473928...............26625693
%C A208175 ...15......2277........473928...........99752346............21002874867
%C A208175 ...51.....33831......26625693........21002874867.........16567902881244
%C A208175 ..187....506493....1496307201......4422202024212......13069424064243420
%C A208175 ..715...7594479...84091222866....931104734002155...10309684155118737894
%C A208175 .2795.113908437.4725865313907.196046229442844736.8132690993759302714128
%H A208175 R. H. Hardin, <a href="/A208175/b208175.txt">Table of n, a(n) for n = 1..220</a>
%e A208175 Some solutions for n=4 k=3
%e A208175 ..0..0..0....0..0..0....0..1..0....0..1..0....0..1..1....0..0..0....0..0..1
%e A208175 ..0..1..2....0..1..0....0..2..2....0..2..3....1..0..0....0..1..1....0..1..0
%e A208175 ..1..2..3....1..2..1....1..2..1....3..0..0....0..1..0....1..2..0....0..0..1
%e A208175 ..1..0..0....0..1..3....1..3..2....2..1..3....1..0..1....1..0..1....1..1..0
%Y A208175 Column 1 is A007581(n-1)
%Y A208175 Column 2 is A205163(n-1)
%K A208175 nonn,tabl
%O A208175 1,2
%A A208175 _R. H. Hardin_ Feb 24 2012