a(1) = 1; a(n+1) = 1 + sum{k|n} a(k), sum is over the positive divisors, k, of n.

Terms

a(0) =1a(1) =2a(2) =4a(3) =6a(4) =10a(5) =12a(6) =20a(7) =22a(8) =32a(9) =38a(10) =52a(11) =54a(12) =80a(13) =82a(14) =106a(15) =122a(16) =154a(17) =156a(18) =208a(19) =210a(20) =268a(21) =294a(22) =350a(23) =352a(24) =454a(25) =466a(26) =550a(27) =588a(28) =700a(29) =702