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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. 2
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, 16, 16, 16, 16, 16, 0, 17, 22, 23, 24, 24, 24, 24, 24, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 0, 20, 26, 30, 30, 32, 32, 34, 34, 34 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,4

COMMENTS

A279405(n) is maximal m such that T(n,m) >= m.

Generally, T(n,k') <= n^2-k if and only if T(n,k) <= n^2-k'.

LINKS

Table of n, a(n) for n=1..70.

Andrey Zabolotskiy, First 9 rows of the triangle and a part of row 10

FORMULA

T(n,0) = 0.

T(n,k) = A000290(n) for k > A000290(n) - T(n,1).

T(n,1) = A047461(n) = A000290(n) - A279403(n,1).

EXAMPLE

The triangle begins:

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 16 16 16 16 16

CROSSREFS

Cf. A000290, A250000, A274947, A274948, A279405, A279403.

Sequence in context: A214926 A268368 A274947 * A171408 A071907 A172369

Adjacent sequences:  A279403 A279404 A279405 * A279407 A279408 A279409

KEYWORD

nonn,tabf

AUTHOR

Andrey Zabolotskiy, Dec 11 2016

STATUS

approved

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Last modified March 26 10:18 EDT 2019. Contains 321491 sequences. (Running on oeis4.)