931392

Appears in sequences

• Unitary superperfect numbers: numbers n such that usigma(usigma(n)) = 2*n, where usigma(n) is the sum of unitary divisors of n (A034448).at n=15A038843
• a(n) = A000010(A000129(n)).at n=17A272040
• Triangle read by rows. T(n, k) = binomial(n, k)^2 * CatalanNumber(k).at n=51A367178
• Irregular triangle read by rows: T(r,c) is the product of the number of standard Young tableaux (A117506) and the number of semistandard Young tableaux (A262030) for partitions of r.at n=49A380611