698544

Appears in sequences

• a(n) = (2n)!(2n+1)!/n!^4, or equally (2n+1)*binomial(2n,n)^2.at n=5A000515
• Triangle of coefficients of Bateman polynomial n!Z_n(-x).at n=33A073768
• Sum of 1-bits between the most and least significant bits summed for all primes in range ]2^n,2^(n+1)].at n=19A095298
• Square of Narayana triangle A001263: View A001263 as a lower triangular matrix. Then the square of that matrix is also lower triangular. Sequence gives this lower triangle, read by rows.at n=49A095801
• Triangle read by rows: T(n,k) (1 <= k <= n) is the sum of the entries in the lower right k X k submatrix of the n X n inverse Hilbert matrix.at n=15A144630
• The sum of the two numbers in an amicable pair, A002025(n) + A002046(n).at n=23A180164
• The sum (in nondecreasing order) of the two numbers in an amicable pair.at n=23A259953
• Denominators of a sequence defined by a modified recurrence for the exponential of the von Mangoldt function.at n=42A277440
• Expansion of e.g.f. -log(1 - x) * exp(-3*x).at n=12A346398
• Triangular table read by rows: T(n,k) is the k-th entry of the main diagonal of the inverse Hilbert matrix of order n.at n=20A348419
• a(n) is the least number with exactly n divisors of the form 5*k+4.at n=38A364600