An approximation to sigma_{5/2}(n): floor( sum_{d|n} d^(5/2) ).

Terms

a(0) =1a(1) =6a(2) =16a(3) =38a(4) =56a(5) =110a(6) =130a(7) =219a(8) =259a(9) =378a(10) =402a(11) =641a(12) =610a(13) =869a(14) =943a(15) =1243a(16) =1192a(17) =1728a(18) =1574a(19) =2199a(20) =2167a(21) =2678a(22) =2537a(23) =3644a(24) =3181a(25) =4062a(26) =4047a(27) =5050a(28) =4529a(29) =6283