90405

Appears in sequences

• G.f.: Sum_{n>=0} x^n * (1+x)^(2^n).at n=9A121688
• Numbers that are divisible by the squares of two distinct primes and whose arithmetic derivative (A003415) is a squarefree number of the form 4k+2.at n=27A368697
• Odd numbers k such that gcd(A276086(sigma(k)-k), A276086(k)) is equal to A276086(k), where A276086 is the primorial base exp-function, and sigma is the sum of divisors function.at n=41A388267