51152domain: NAppears in sequencesn*(n-1)*(n^2-n+4)/6.at n=24A103290The fourth row of the ED2 array A167560.at n=22A167561Riordan array (((1+x)/(1-x-x^2))^m, x*A000108(x)), m=3.at n=57A185678a(n) = Sum_{-n<i<n, -n<j<n, gcd{i,j}=2} (n-|i|)*(n-|j|).at n=23A331772