Number of subsets of {1..n} whose harmonic mean is an integer.

Terms

a(0) =1a(1) =2a(2) =3a(3) =4a(4) =5a(5) =12a(6) =13a(7) =14a(8) =15a(9) =18a(10) =19a(11) =26a(12) =27a(13) =30a(14) =53a(15) =54a(16) =55a(17) =100a(18) =101a(19) =180a(20) =203a(21) =210a(22) =211a(23) =378a(24) =379a(25) =382a(26) =383a(27) =1092a(28) =1093a(29) =2020