Dirichlet convolution of d(n) (number of divisors of n) with primes (with 1).

Terms

a(0) =1a(1) =4a(2) =5a(3) =12a(4) =9a(5) =25a(6) =15a(7) =37a(8) =28a(9) =45a(10) =31a(11) =86a(12) =39a(13) =75a(14) =67a(15) =109a(16) =55a(17) =143a(18) =63a(19) =158a(20) =107a(21) =139a(22) =81a(23) =264a(24) =106a(25) =179a(26) =152a(27) =248a(28) =109a(29) =319