A180372 1/9 the number of triangular nXnXn arrays of integers in 1..9 with no element or any of its neighbors having the same value.

1, 56, 6720, 1290240, 392232960

Offset

1,2

Links

Table of n, a(n) for n=1..5.

Crossrefs

Sequence in context: A278777 A202565 A213693 * A255960 A201240 A329104

Adjacent sequences: A180369 A180370 A180371 * A180373 A180374 A180375

Keyword

nonn

Author

R. H. Hardin, Sep 01 2010

Status

approved