Numbers n such that sigma(n) divides sum_{k=1..n} tau(k), where tau(k) is the number of divisors of k (A000005) and sigma(n) is the sum of divisors of n (A000203).

A182169

Numbers n such that sigma(n) divides sum_{k=1..n} tau(k), where tau(k) is the number of divisors of k (A000005) and sigma(n) is the sum of divisors of n (A000203).

Terms

    a(0) =1a(1) =2a(2) =7a(3) =19a(4) =358a(5) =3845a(6) =31138a(7) =36461a(8) =4286729a(9) =81945545a(10) =2059172170a(11) =3071920146a(12) =9331669953a(13) =19026491086

External references