Odd squares k, multiples of 3 and non-multiples of 5, such that sigma(k)/k >= 5/3.

Terms

a(0) =441a(1) =3969a(2) =21609a(3) =35721a(4) =53361a(5) =74529a(6) =127449a(7) =159201a(8) =184041a(9) =194481a(10) =233289a(11) =314721a(12) =321489a(13) =370881a(14) =393129a(15) =423801a(16) =480249a(17) =603729a(18) =670761a(19) =741321a(20) =815409a(21) =974169a(22) =1058841a(23) =1147041a(24) =1238769a(25) =1432809a(26) =1535121a(27) =1640961a(28) =1656369a(29) =1750329