98969domain: NAppears in sequencesNumber of simple imperfect squared rectangles of order n up to symmetry.at n=19A002881Harmonic mean of digits is 8.at n=21A062185a(0) = a(1) = a(2) = 1; a(n) = a(n-3) + Sum_{k=0..n-4} a(k) * a(n-k-4).at n=26A343304