142532domain: NAppears in sequencesa(n) = n*(n^4 + 10*n^3 + 35*n^2 + 50*n + 144)/120.at n=25A051745Number of arrangements of n+2 nonzero numbers x(i) in -8..8 with the sum of x(i)*x(i+1) equal to zero.at n=3A188248Number of arrangements of 6 nonzero numbers x(i) in -n..n with the sum of x(i)*x(i+1) equal to zero.at n=7A188252