Floor(n(n - 1)/31).

Terms

a(0) =0a(1) =0a(2) =0a(3) =0a(4) =0a(5) =0a(6) =0a(7) =1a(8) =1a(9) =2a(10) =2a(11) =3a(12) =4a(13) =5a(14) =5a(15) =6a(16) =7a(17) =8a(18) =9a(19) =11a(20) =12a(21) =13a(22) =14a(23) =16a(24) =17a(25) =19a(26) =20a(27) =22a(28) =24a(29) =26