114662domain: NAppears in sequencesa(1)=2. For n >=2, a(n) = the least integer >= a(n-1) that is not coprime to both a(n-1)+1 and a(n-1).at n=36A140525Number of nondecreasing arrangements of 6 numbers in -(n+4)..(n+4) with sum zero and not more than two numbers equal.at n=15A188239