cp's OEIS Frontend

A188252 Number of arrangements of 6 nonzero numbers x(i) in -n..n with the sum of x(i)*x(i+1) equal to zero.

%I A188252 #6 Jul 22 2025 11:05:45
%S A188252 0,300,1632,7092,16484,43440,75080,142532,232432,380244,525668,841504,
%T A188252 1099064,1531092,2070976,2785252,3396316,4539424,5414024,6981628,
%U A188252 8554708,10387240,11982424,15101088,17498972
%N A188252 Number of arrangements of 6 nonzero numbers x(i) in -n..n with the sum of x(i)*x(i+1) equal to zero.
%C A188252 Row 4 of A188249
%e A188252 Some solutions for n=4
%e A188252 .-4....2...-4...-1....2....4....3....4....3....3....1...-3...-1...-2...-3....3
%e A188252 ..1...-3...-2....2...-1...-1....1...-2...-2....4...-4....3....3....3...-1...-4
%e A188252 .-2...-3...-4...-1...-2...-2...-2....2....2....4...-4....1...-2....1...-2...-4
%e A188252 .-4....3....4...-4....1....2...-4...-2...-1...-2....1....2....3....3....2...-4
%e A188252 ..1....3...-3...-3...-1....2....3...-4...-4....4...-4...-4....3....1....1....4
%e A188252 ..2...-1...-4....4...-3....1....1...-2...-2...-3....1...-3....2...-3...-3...-1
%K A188252 nonn
%O A188252 1,2
%A A188252 _R. H. Hardin_ Mar 25 2011