Number of digits in n-th even perfect number (A000396).

Terms

a(0) =1a(1) =2a(2) =3a(3) =4a(4) =8a(5) =10a(6) =12a(7) =19a(8) =37a(9) =54a(10) =65a(11) =77a(12) =314a(13) =366a(14) =770a(15) =1327a(16) =1373a(17) =1937a(18) =2561a(19) =2663a(20) =5834a(21) =5985a(22) =6751a(23) =12003a(24) =13066a(25) =13973a(26) =26790a(27) =51924a(28) =66530a(29) =79502