INVERT transform of A008805 (triangular numbers repeated).

Terms

a(0) =1a(1) =2a(2) =6a(3) =14a(4) =35a(5) =85a(6) =208a(7) =508a(8) =1241a(9) =3032a(10) =7407a(11) =18096a(12) =44209a(13) =108005a(14) =263861a(15) =644625a(16) =1574849a(17) =3847430a(18) =9399452a(19) =22963302a(20) =56100424a(21) =137055967a(22) =334834156a(23) =818015548a(24) =1998450352a(25) =4882307945a(26) =11927707309a(27) =29139948412a(28) =71190260748