a(n) is the (2n)-th term of the n-fold self-convolution of the sum of divisors function sigma.
A340993
a(n) is the (2n)-th term of the n-fold self-convolution of the sum of divisors function sigma.
Terms
- a(0) =1a(1) =3a(2) =17a(3) =120a(4) =885a(5) =6713a(6) =51932a(7) =407214a(8) =3224845a(9) =25733325a(10) =206584437a(11) =1666561042a(12) =13498994796a(13) =109713432390a(14) =894291885000
External references
- oeis: A340993