Numbers k such that sigma(k) is a harmonic number.

Terms

a(0) =1a(1) =5a(2) =12a(3) =76a(4) =136a(5) =139a(6) =178a(7) =269a(8) =276a(9) =308a(10) =427a(11) =429a(12) =446a(13) =455a(14) =501a(15) =581a(16) =611a(17) =612a(18) =738a(19) =932a(20) =1576a(21) =1637a(22) =2952a(23) =2969a(24) =3184a(25) =3204a(26) =4647a(27) =4975a(28) =5400a(29) =5458