cp's OEIS Frontend

A188356 Number of arrangements of n+1 numbers x(i) in -7..7 with the sum of x(i)*x(i+1) equal to zero.

%I A188356 #6 Jul 22 2025 11:09:49
%S A188356 29,435,1569,22583,163745,2295051,25217201,355442823,4602176797,
%T A188356 65556183495,902973314217,12966307902587,183476638021301,
%U A188356 2650029026701115,38023581868527461,551634055112635223
%N A188356 Number of arrangements of n+1 numbers x(i) in -7..7 with the sum of x(i)*x(i+1) equal to zero.
%C A188356 Column 7 of A188358
%e A188356 Some solutions for n=4
%e A188356 .-6...-1....2...-1...-3....3....7...-1....0...-3...-1....3...-7....7....3...-1
%e A188356 ..0....0....0....0...-5....0...-5....0...-6....6...-6....2....0...-3....0....0
%e A188356 ..3....1....2....5....3...-5...-3....2....1....2...-1....0...-3...-3....0....2
%e A188356 ..1....4....6....4....0....0....5...-5....3...-3...-6....3...-7....6....0....0
%e A188356 .-3...-1...-2...-5...-2...-5....7...-2....1...-4....3...-2....3....5...-5...-5
%K A188356 nonn
%O A188356 1,1
%A A188356 _R. H. Hardin_ Mar 28 2011