A271845 Number of ways to move elements of an nXnXn triangular array to themselves or a neighbor, with no 2-cycles and with no more than 1-1 elements moved to themselves.

0, 2, 2, 42, 580, 31892, 3193380, 800156720, 442390366776, 566421064781268, 1649994557114019556

Offset

1,2

Comments

Column 1 of A271852.

Links

Table of n, a(n) for n=1..11.

Example

Some solutions for n=4
.....6........6........5........5........6........5........5........5
....2.6......2.3......6.1......6.1......2.5......4.1......6.1......6.1
...6.1.6....4.5.5....5.2.6....6.2.5....2.5.6....4.4.6....5.6.1....5.2.5
..2.3.1.3..2.3.4.1..4.1.2.3..2.3.4.1..2.3.2.3..2.3.3.3..4.1.4.1..4.1.4.1
Element moves: 0=itself 1=nw 2=ne 3=w 4=e 5=sw 6=se, reciprocals total 7

Crossrefs

Cf. A271852.

Sequence in context: A153434 A152016 A264516 * A348226 A280061 A349602

Adjacent sequences: A271842 A271843 A271844 * A271846 A271847 A271848

Keyword

nonn

Author

R. H. Hardin, Apr 15 2016

Status

approved