2521260

Appears in sequences

• Expansion of 1/(1-4*x)^(21/2).at n=5A020932
• a(n) is the smallest entry of the n-th column of the matrix of Super Catalan numbers S(m,n).at n=15A173781
• a(n) = (6*n)!*(2*n)!/((4*n)!*(3*n)!*n!).at n=5A211419
• a(n) = 1/n! * ((n+1)*n)!/Gamma(1 + (n+1)*n/2) * Gamma(1 + (n-1)*n/2)/((n-1)*n)!.at n=5A332231
• Numbers k such that sigma(k) = psi(k) + phi(k) + omega(k)^8.at n=1A392077