A255487 Number of polyhypercubes or 4-dimensional polyominoes with n cells (regarding mirror-images as distinct).

1, 1, 1, 2, 7, 27, 164, 1316, 12757, 134174, 1474341, 16588434

Offset: 0

Author

N. J. A. Sloane, Mar 01 2015

Keywords

• hard
• nonn

References

• Don Reble, Personal communication, Feb 25 2015

Crossrefs

Cf. A049429, A049430, A068870.

Formula

a(n) = A006760(n) + A006765(n) + A006766(n) + signum(n-1) for n >= 1. - Sean A. Irvine, Jul 19 2017