66885

Appears in sequences

• Indices of primes in sequence defined by A(0) = 91, A(m) = 10*A(m-1) - 9 for m > 0.at n=16A100997
• Numbers for which the number of prime divisors counted with multiplicity and the sum of the distinct prime divisors are both perfect.at n=26A233563
• Let f(x) = 1 + Sum_{j>=4} (|mu(j)| - |mu(j-1)|)*x^j, where mu(n) is the Möbius function (A008683). Then a(n) is n times the coefficient of x^n in the expansion of log(f(x)).at n=49A262400
• Number of (undirected) cycles in the n-flower graph.at n=7A368191
• Odd numbers k for which A003961(k) > 2*k and A003961(k)-2*k OR A003961(k)-sigma(k) = A003961(k)-2*k, where OR is bitwise-or (A003986) and A003961 is fully multiplicative with a(p) = nextprime(p).at n=7A388029