57645

Appears in sequences

• Numbers k such that phi(k) = phi(k+1).at n=32A001274
• Odd numbers n such that sigma(n) = sigma(2*n-1).at n=2A275370
• Numbers k whose sum of divisors equals the sum of divisors of 2*k-1.at n=13A289738
• Nonzero coefficients of the polynomials (x + d/dx)^n x^2, in row-major order.at n=40A330209
• Expansion of e.g.f. exp(x^2/2 * (1 + x)).at n=10A373740