1528436

Appears in sequences

• First numerator and then denominator of the central elements of the 1/3-Pascal triangle (by row).at n=24A046543
• First denominator and then numerator of the central elements of the 1/3-Pascal triangle (by row).at n=25A046544
• Distinct numbers in writing first numerator and then denominator of the central elements of the 1/3-Pascal triangle (by row).at n=12A046545
• a(n) = C(n)*(9*n + 1) where C(n) = Catalan numbers (A000108).at n=10A050479
• Reversion of y - y^2 + y^4 + y^5.at n=16A063034
• G.f. is the polynomial (Product_{k=1..19} (1 - x^(3*k)))/(1-x)^19.at n=8A162639
• Square array read by ascending antidiagonals: T(n,k) = (2*k)!/k!^2 * ( (2*n*k)! * ((n + 2)*k)! )/( (n*k)! * ((n + 1)*k)!^2 ) for n, k > = 0.at n=30A364509
• Numbers k such that sigma(k) = psi(k) + phi(k) + tau(k)^2.at n=24A390421