1,6
Table of n, a(n) for n=1..11.
Three collinear points in an n X n grid A000938 ; n X n X n grid A157882
Sequence in context: A248446 A202404 A203882 * A157825 A205607 A205438
Adjacent sequences: A178281 A178282 A178283 * A178285 A178286 A178287
nonn
R. H. Hardin, suggested by R. J. Mathar in the Sequence Fans Mailing List, May 24 2010
approved