14395920domain: NAppears in sequencesNumber of labeled pure 2-complexes on n nodes (0-simplexes) with 5 2-simplexes and 9 1-simplexes.at n=17A054558Numbers that can be expressed as the difference of the squares of primes in exactly nineteen distinct ways.at n=16A092015a(n) = 16^n * Sum_{k=0..n} (-1)^k*binomial(-1/2, k)^2.at n=6A358362