# Different squares on an n X n lattice

David Wilson davidwwilson at comcast.net
Tue Jun 7 14:16:20 CEST 2005

```> Add:
>
> %S A108279
> 1,3,5,8,11,15,18,23,28,33,38,45,51,58,65,73,80,89,97,107,116,126,134,146,
> ....
> %N A108279 a(n) = number of squares with corners on an n X n grid,
> distinct
> up to congruence.
> %Y A108279 See A002415, A024206.
> %O A108279 1,3
>
> I don't understand the proposed offset. The first term describes the 2 X 2
> grid, which forms 1 square. Offset should therefore be 2.
>
> Hugo Pfoertner

As usual these days, I can't get anything right.  I thought that an initial
a(1) = 0
would be appropriate, hence:

%S A108279
0,1,3,5,8,11,15,18,23,28,33,38,45,51,58,65,73,80,89,97,107,116,126,134,146,
%T A108279
158,169,180,192,204,218,228,243,257,270,285,302,316,331,346,364,379,397,
%U A108279
414,433,451,468,484,505,523,544,563,584,603,625,646,669,691,713,733,759
%N A108279 a(n) = number of squares with corners on an n X n grid, distinct
up to congruence.
%Y A108279 See A002415, A024206.
%O A108279 1,3

```