a(n) = 1 + sigma(n) + sigma(n)^2 + sigma(n)^3 + sigma(n)^4 + sigma(n)^5 + sigma(n)^6.

Terms

a(0) =7a(1) =1093a(2) =5461a(3) =137257a(4) =55987a(5) =3257437a(6) =299593a(7) =12204241a(8) =5229043a(9) =36012943a(10) =3257437a(11) =499738093a(12) =8108731a(13) =199411801a(14) =199411801a(15) =917087137a(16) =36012943a(17) =3611342281a(18) =67368421a(19) =5622910567a(20) =1108378657a(21) =2238976117a(22) =199411801a(23) =47446779661a(24) =917087137a(25) =5622910567