A292152 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 don't have any symmetry.

0, 0, 0, 0, 0, 40, 0, 0, 368, 1432, 0, 0, 1704, 10992, 50992, 0, 0, 5704, 53784, 369776, 1925464, 0, 0, 15400, 198696, 1885128, 13903624, 85773968, 0, 0, 36096, 606264, 7572896, 74743584, 620821688, 4424756040

Offset

1,6

References

Walter Krämer, Denkste! Trugschlüsse aus der Welt der Zahlen und des Zufalls. Campus Verlag, Frankfurt/Main, 1996. Chapter 4, pp. 71-82.

Links

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

Formula

a(n) = A090642(n) - A292153(n).

Example

The triangle begins:
  0;
  0,  0;
  0,  0,    40;
  0,  0,   368,   1432;
  0,  0,  1704,  10992,  50992;
  0,  0,  5704,  53784,  369776,  1925464;
  0,  0, 15400, 198696, 1885128, 13903624, 85773968;
.
The following configuration of 6 picked points from a 7X7 grid is one of the T(7,6)=a(28)=13903624 configurations without symmetry. It is of some historical interest, because when it was drawn in Germany's "Lotto 6 aus 49", there was only one person with a winning bet receiving a payout of 22 million DM (Deutsche Mark).
.
  o o o o o o o
  o o o o o o o
  o o o o X o o
  o o X o o o o
  o o o o o o X
  X X X o o o o
  o o o o o o o

Crossrefs

Cf. A090642, A098485, A098487, A291716, A291717, A291718, A292153, A292154, A292155, A292156.

Sequence in context: A173364 A023931 A067159 * A331907 A247404 A013373

Adjacent sequences: A292149 A292150 A292151 * A292153 A292154 A292155

Keyword

nonn,tabl,more

Author

Hugo Pfoertner, Sep 17 2017

Status

approved