A153914 Number of planar n X n X n binary triangular grids symmetric under 120 degree rotation with no more than 2 ones in any 4 X 4 X 4 subtriangle.

1, 2, 1, 1, 2, 4, 9, 26, 49, 114, 335, 860, 2642, 11403, 31366, 122074, 649249, 2617092, 13723850, 92885894, 495630474, 3323403054, 28712335687, 193014843154, 1677713274836, 19022134210553, 161885710747705, 1807982773217565

Offset

0,2

Links

Table of n, a(n) for n=0..27.

Crossrefs

Sequence in context: A210112 A024735 A024957 * A151893 A326566 A213953

Adjacent sequences: A153911 A153912 A153913 * A153915 A153916 A153917

Keyword

nonn

Author

R. H. Hardin, Jan 03 2009

Status

approved