a(n) = 1111111 in base n.

Terms

a(0) =7a(1) =127a(2) =1093a(3) =5461a(4) =19531a(5) =55987a(6) =137257a(7) =299593a(8) =597871a(9) =1111111a(10) =1948717a(11) =3257437a(12) =5229043a(13) =8108731a(14) =12204241a(15) =17895697a(16) =25646167a(17) =36012943a(18) =49659541a(19) =67368421a(20) =90054427a(21) =118778947a(22) =154764793a(23) =199411801a(24) =254313151a(25) =321272407a(26) =402321277a(27) =499738093