97690domain: NAppears in sequencesSum of staircase twin primes according to the rule: top * bottom + next top.at n=19A135286a(n) is the number of quintuples (a_1,a_2,a_3,a_4,a_5) having all terms in {1,...,n} such that there exists a pentagon with these side-lengths.at n=10A346637