139126domain: NAppears in sequencesNumber of different values assumed by a/b+c/d as a,b,c,d range between 1 and n.at n=33A119868Number of compositions of n with weakly increasing differences.at n=45A325546Sum of Fibonacci and tribonacci numbers: a(n) = A000073(n) + A000045(n).at n=22A338192