cp's OEIS Frontend

A181031 Array read by antidiagonals: T(n,k) = number of n X k binary matrices with no initial bit string in any row or column divisible by 4.

%I A181031 #10 Jun 06 2017 17:35:19
%S A181031 1,1,1,1,2,1,1,3,3,1,1,5,7,5,1,1,8,17,17,8,1,1,13,41,63,41,13,1,1,21,
%T A181031 99,227,227,99,21,1,1,34,239,827,1234,827,239,34,1,1,55,577,2999,6743,
%U A181031 6743,2999,577,55,1,1,89,1393,10897,36787,55447,36787,10897,1393,89,1,1,144
%N A181031 Array read by antidiagonals: T(n,k) = number of n X k binary matrices with no initial bit string in any row or column divisible by 4.
%C A181031 A089980 is essentially the same array (see the Comments by _Steve Butler_ in A006506). - _N. J. A. Sloane_, Jan 27 2015
%H A181031 R. H. Hardin, <a href="/A181031/b181031.txt">Table of n, a(n) for n=1..1057</a>
%e A181031 Table starts
%e A181031 .1..1....1......1.......1.........1...........1............1..............1
%e A181031 .1..2....3......5.......8........13..........21...........34.............55
%e A181031 .1..3....7.....17......41........99.........239..........577...........1393
%e A181031 .1..5...17.....63.....227.......827........2999........10897..........39561
%e A181031 .1..8...41....227....1234......6743.......36787.......200798........1095851
%e A181031 .1.13...99....827....6743.....55447......454385......3729091.......30584687
%e A181031 .1.21..239...2999...36787....454385.....5598861.....69050253......851302029
%e A181031 .1.34..577..10897..200798...3729091....69050253...1280128950....23720149995
%e A181031 .1.55.1393..39561.1095851..30584687...851302029..23720149995...660647962955
%e A181031 .1.89.3363.143677.5980913.250916131.10496827403.439621976195.18403310404291
%e A181031 Some solutions for 5X5
%e A181031 ..1..1..1..1..1....1..1..1..1..1....1..1..1..1..1....1..1..1..1..1
%e A181031 ..1..0..1..0..1....1..0..1..0..1....1..0..1..0..1....1..0..1..0..1
%e A181031 ..1..1..0..1..0....1..1..0..1..0....1..1..0..1..0....1..1..0..1..0
%e A181031 ..1..0..1..0..1....1..0..1..0..1....1..0..1..0..1....1..0..1..0..1
%e A181031 ..1..1..0..1..0....1..1..0..1..1....1..1..1..1..0....1..1..1..1..1
%Y A181031 Cf. A089980.
%K A181031 nonn,tabl
%O A181031 1,5
%A A181031 _R. H. Hardin_, Sep 30 2010