4875112domain: NAppears in sequencesNumber of arrangements of n+2 nonzero numbers x(i) in -6..6 with the sum of x(i)*x(i+1) equal to zero.at n=5A188246Number of arrangements of 8 nonzero numbers x(i) in -n..n with the sum of x(i)*x(i+1) equal to zero.at n=5A188254