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A292154 Triangle T(m,k) read by rows, where T(m,k) is the number of ways in which 1<=k<=m positions can be picked in an m X m square grid such that the picked positions have both a point symmetry and a line symmetry. 9
1, 4, 6, 9, 36, 8, 16, 120, 24, 56, 25, 300, 72, 186, 50, 36, 630, 144, 473, 128, 648, 49, 1176, 288, 1024, 320, 1660, 728, 64, 2016, 480, 1952, 608, 3560, 1520, 7326 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..36.

FORMULA

a(n) = A292153(n) - A292155(n) - A292156(n).

a(n) = A291717(n) - A292155(n).

a(n) = A291718(n) - A292156(n).

EXAMPLE

The triangle begins:

   1;

   4,    6;

   9,   36,   8;

  16,  120,  24,   56;

  25,  300,  72,  186,  50;

  36,  630, 144,  473, 128,  648;

  49, 1176, 288, 1024, 320, 1660,  728;

  64, 2016, 480, 1952, 608, 3560, 1520, 7326;

.

  o o o o o o

  X o o X o o

  o o o o o o

  X o o X o o

  o o o o o o

  X o o X o o

is one of the T(6,6)=a(21)=648 configurations with both types of symmetry.

.

  o o X o o o

  o X o o o o

  o o o X o o

  o o o o o X

  o o o o X o

  o o o o o o

is one of the T(6,5)=a(20)=128 configurations with both types of symmetry.

CROSSREFS

Cf. A090642, A098485, A098487, A291716, A291717, A291718, A292152, A292153, A292155, A292156.

Sequence in context: A081614 A192220 A215477 * A291717 A303699 A292153

Adjacent sequences:  A292151 A292152 A292153 * A292155 A292156 A292157

KEYWORD

nonn,tabl,more

AUTHOR

Hugo Pfoertner, Sep 17 2017

STATUS

approved

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Last modified April 9 17:09 EDT 2020. Contains 333361 sequences. (Running on oeis4.)