a(n) = the smallest number m such that gcd(tau(m), sigma(m)) = n where tau(k) = the number of the divisors of k (A000005) and sigma(k) = the sum of the divisors of k (A000203).
A324554
a(n) = the smallest number m such that gcd(tau(m), sigma(m)) = n where tau(k) = the number of the divisors of k (A000005) and sigma(k) = the sum of the divisors of k (A000203).
Terms
- a(0) =1a(1) =3a(2) =18a(3) =6a(4) =648a(5) =20a(6) =2916a(7) =30a(8) =288a(9) =304a(10) =82944a(11) =60a(12) =36864a(13) =832a(14) =16200a(15) =168a(16) =5509980288a(17) =612a(18) =31719424a(19) =432a(20) =23328a(21) =44032a(22) =247669456896a(23) =420a(24) =9487368a(25) =258048a(26) =14112a(27) =2496a(29) =4176a(30) =26843545600
External references
- oeis: A324554