Boris Stechkin's function.

Terms

a(0) =0a(1) =0a(2) =1a(3) =5a(4) =15a(5) =33a(6) =64a(7) =107a(8) =171a(9) =252a(10) =359a(11) =490a(12) =656a(13) =844a(14) =1079a(15) =1346a(16) =1656a(17) =2006a(18) =2415a(19) =2859a(20) =3373a(21) =3927a(22) =4550a(23) =5233a(24) =5993a(25) =6793a(26) =7690a(27) =8653a(28) =9697a(29) =10809