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A105074 Number of ways to fill in an n X n grid such that the digits of each row and each column form a square number. 1
3, 4, 13, 14, 76, 108, 459, 844 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Leading zeros are forbidden in the rows and columns.

LINKS

Table of n, a(n) for n=1..8.

EXAMPLE

The 1 X 1 crosssquare-puzzle is easy; the only solutions are 1, 4, and 9.

The 4 solutions for n=2 are [16/64], [36/64], [64/49], [81/16].

Or, writing them as 2 X 2 matrices,

  16  36  64  81

  64  64  49  16

CROSSREFS

Sequence in context: A095790 A109474 A053910 * A208847 A278426 A293280

Adjacent sequences:  A105071 A105072 A105073 * A105075 A105076 A105077

KEYWORD

nonn,base,more

AUTHOR

Matthijs Coster, Apr 29 2005

EXTENSIONS

Corrected and extended by Luca Petrone, Jan 08 2017

STATUS

approved

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Last modified December 17 02:27 EST 2018. Contains 318192 sequences. (Running on oeis4.)