Number of digits in n-th even perfect number written in base 8.

Terms

a(0) =1a(1) =2a(2) =3a(3) =5a(4) =9a(5) =11a(6) =13a(7) =21a(8) =41a(9) =59a(10) =71a(11) =85a(12) =347a(13) =405a(14) =853a(15) =1469a(16) =1521a(17) =2145a(18) =2835a(19) =2949a(20) =6459a(21) =6627a(22) =7475a(23) =13291a(24) =14467a(25) =15473a(26) =29665a(27) =57495a(28) =73669a(29) =88033