1058841

Appears in sequences

• Numbers of form 7^i*9^j, with i, j >= 0.at n=29A025631
• If n = (p_1)^(m_1)...(p_k)^(m_k) then a(n) = (p_1)^((p_1)^(m_1) - 1)...(p_k)((p_k)^(m_k) - 1).at n=20A036879
• Squares that are a difference between 2 positive cubes.at n=18A038596
• Squares expressible as the sum of two positive cubes in at least one way.at n=22A050802
• Numbers n such that the squarefree kernel of n is equal to the number of divisors of n.at n=32A070226
• Triangle read by rows: Stirling2 triangle with scaled diagonals (powers of 7).at n=22A075502
• Second column of triangle A075502.at n=5A075921
• Squares that are both a sum and a difference of two positive cubes.at n=1A230717
• Perfect powers of the form x^3 + y^3 where x and y are positive integers.at n=27A267088
• Perfect powers of the form x^3 + y^3 where x and y are distinct positive integers.at n=18A267416
• Magic sums of 3 X 3 semimagic squares of squares whose rows, columns, and at least one of the two main diagonals sum to the same number.at n=8A271021
• Integers whose arithmetic derivative is equal to their Dedekind function.at n=33A301939
• Numbers k for which A344998(k) = A344999(k).at n=37A345003
• Odd numbers whose arithmetic derivative (A003415) is equal to Dedekind psi (A001615) applied to the same number.at n=5A345005
• a(n) is the smallest number k such that k*n is a term of A072873.at n=20A365637
• Odd squares k, multiples of 3 and non-multiples of 5, such that sigma(k)/k >= 5/3.at n=22A388016
• Irregular triangle T(n, k) = Product_{i=1..n} prime(i)^(k mod prime(i)), with n >= 0, and 0 <= k < A002110(n), read by rows.at n=59A391933