cp's OEIS Frontend

A279406 Irregular triangle read by rows: T(n,k) (n>=1, 0 <= k <= n^2) = minimal number of squares attacked by k queens on an n X n toroidal board.

%I A279406 #7 Dec 15 2016 23:48:50
%S A279406 0,1,0,4,4,4,4,0,9,9,9,9,9,9,9,9,9,0,12,14,15,15,16,16,16,16,16,16,16,
%T A279406 16,16,16,16,16,0,17,22,23,24,24,24,24,24,25,25,25,25,25,25,25,25,25,
%U A279406 25,25,25,25,25,25,25,25,0,20,26,30,30,32,32,34,34,34
%N A279406 Irregular triangle read by rows: T(n,k) (n>=1, 0 <= k <= n^2) = minimal number of squares attacked by k queens on an n X n toroidal board.
%C A279406 A279405(n) is maximal m such that T(n,m) >= m.
%C A279406 Generally, T(n,k') <= n^2-k if and only if T(n,k) <= n^2-k'.
%H A279406 Andrey Zabolotskiy, <a href="http://pastebin.com/XgtJ6Bew">First 9 rows of the triangle and a part of row 10</a>
%F A279406 T(n,0) = 0.
%F A279406 T(n,k) = A000290(n) for k > A000290(n) - T(n,1).
%F A279406 T(n,1) = A047461(n) = A000290(n) - A279403(n,1).
%e A279406 The triangle begins:
%e A279406 0 1
%e A279406 0 4 4 4 4
%e A279406 0 9 9 9 9 9 9 9 9 9
%e A279406 0 12 14 15 15 16 16 16 16 16 16 16 16 16 16 16 16
%Y A279406 Cf. A000290, A250000, A274947, A274948, A279405, A279403.
%K A279406 nonn,tabf
%O A279406 1,4
%A A279406 _Andrey Zabolotskiy_, Dec 11 2016