cp's OEIS Frontend

A331462 Triangle read by rows: T(n,k) is the number of n X n binary matrices with k=0..n^2 ones forming a polyomino, under action of dihedral group of the square D_4.

%I A331462 #30 Jul 05 2020 12:52:38
%S A331462 0,0,1,0,1,1,1,1,0,3,2,5,6,10,8,7,3,1,0,3,4,8,17,33,68,119,195,261,
%T A331462 300,257,169,66,20,3,1,0,6,6,16,32,82,189,470,1076,2422,5010,9732,
%U A331462 17145,27399,38680,47560,49325,41872,27864,14095,5280,1470,302,48,6,1
%N A331462 Triangle read by rows: T(n,k) is the number of n X n binary matrices with k=0..n^2 ones forming a polyomino, under action of dihedral group of the square D_4.
%C A331462 By forming a polyomino it is meant that there is at least one 1 and that all the 1's are connected horizontally or vertically.
%H A331462 Jean-Luc Manguin, <a href="/A331462/b331462.txt">Table of n, a(n) for n = 0..97</a>
%H A331462 Jean-Luc Manguin, <a href="/A331462/a331462.pdf">Illustration of a(3) and comparison with A268416</a>
%e A331462 Triangle begins:
%e A331462   0;
%e A331462   0, 1;
%e A331462   0, 1, 1, 1, 1;
%e A331462   0, 3, 2, 5, 6, 10, 8, 7, 3, 1;
%e A331462   0, 3, 4, 8, 17, 33, 68, 119, 195, 261, 300, 257, 169, 66, 20, 3, 1;
%e A331462   ...
%Y A331462 Cf. A054252, A268416.
%K A331462 nonn,tabf
%O A331462 0,10
%A A331462 _Jean-Luc Manguin_, Jan 17 2020