a(n) = Sum_{d|n} prime(n/d)^d.

Terms

a(0) =2a(1) =7a(2) =13a(3) =32a(4) =43a(5) =129a(6) =145a(7) =405a(8) =660a(9) =1417a(10) =2079a(11) =5999a(12) =8233a(13) =18903a(14) =37271a(15) =74912a(16) =131131a(17) =300239a(18) =524355a(19) =1139985a(20) =2180263a(21) =4372491a(22) =8388691a(23) =17853809a(24) =33715580a(25) =68704969a(26) =136183123a(27) =274127445a(28) =536871021a(29) =1100025921