18068

Appears in sequences

• Numbers n whose sum of divisors and number of divisors are both triangular numbers.at n=38A070996
• Triangle of coefficients of polynomials u(n,x) jointly generated with A210750; see the Formula section.at n=50A210749
• a(n) = ceiling(li(2*2^n) - li(2^n)) - (pi(2*2^n) - pi(2^n)) with li(x) the logarithmic integral and pi(x) the prime counting function.at n=42A223853
• G.f. satisfies: A(x) = Sum_{n>=0} x^n * (3 + A(x)^n)^n.at n=5A247331