Sigmabonacci numbers: a(n)=a(n-1)+Sigma(a(n-2)). Sigma(n)=Sum of divisors of n.

Terms

a(0) =1a(1) =1a(2) =2a(3) =3a(4) =6a(5) =10a(6) =22a(7) =40a(8) =76a(9) =166a(10) =306a(11) =558a(12) =1260a(13) =2508a(14) =6876a(15) =13596a(16) =31068a(17) =66012a(18) =144636a(19) =298692a(20) =656532a(21) =1411650a(22) =3114050a(23) =6907892a(24) =12800744a(25) =24982760a(26) =51166280a(27) =112488680a(28) =239410280a(29) =501240080