Odd numbers k that are closer to being perfect than previous terms and also satisfy the condition that gcd(k, A003961(k)) is equal to gcd(sigma(k), A003961(k)), where A003961(n) is fully multiplicative with a(prime(k)) = prime(k+1), and sigma is the sum of divisors function.
A386421
Odd numbers k that are closer to being perfect than previous terms and also satisfy the condition that gcd(k, A003961(k)) is equal to gcd(sigma(k), A003961(k)), where A003961(n) is fully multiplicative with a(prime(k)) = prime(k+1), and sigma is the sum of divisors function.
Terms
- a(0) =1a(1) =3a(2) =9a(3) =21a(4) =63a(5) =135a(6) =855a(7) =1485a(8) =25245a(9) =34155a(10) =43785a(11) =46035a(12) =1665825a(13) =1805475a(14) =22982505a(15) =125011845a(16) =127371195a(17) =657814575
External references
- oeis: A386421