cp's OEIS Frontend

A271615 Number of ways to reciprocally link elements of an n X n X n triangular array with themselves or a neighbor, with no more than 6 elements linked to themselves.

%I A271615 #6 Jun 15 2017 21:54:02
%S A271615 1,4,27,406,7764,222936,18314708,1182352612,30892003921,3065366376540,
%T A271615 2070868688611599,493143363040812884,25923218026065797712,
%U A271615 11188107558636007931696,60230981411511158858617306,63827420909748305015725846472,9319830273030294425399538816052
%N A271615 Number of ways to reciprocally link elements of an n X n X n triangular array with themselves or a neighbor, with no more than 6 elements linked to themselves.
%C A271615 Column 6 of A271617.
%e A271615 Some solutions for n=4
%e A271615 .....0........6........0........6........6........6........0........0
%e A271615 ....6.0......0.1......5.0......0.1......0.1......0.1......0.0......0.0
%e A271615 ...5.1.5....5.0.0....2.0.6....5.0.6....5.4.3....4.3.6....5.4.3....5.6.6
%e A271615 ..2.0.2.0..2.4.3.0..0.4.3.1..2.0.0.1..2.0.4.3..0.0.0.1..2.0.0.0..2.0.1.1
%e A271615 Element moves: 0=itself 1=nw 2=ne 3=w 4=e 5=sw 6=se, reciprocals total 7
%Y A271615 Cf. A271617.
%K A271615 nonn
%O A271615 1,2
%A A271615 _R. H. Hardin_, Apr 10 2016
%E A271615 a(14)-a(17) from _Alois P. Heinz_, Jun 15 2017