This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A161514 #9 Aug 07 2018 03:41:04 %S A161514 1,2,3,5,9,11,13,21,41,59,71,85,347,405,853,1469,1521,2145,2835,2949, %T A161514 6459,6627,7475,13291,14467,15473,29665,57495,73669,88033,144061, %U A161514 504559,572955,838525,932179,1984147,2014251,4648395,8977945,13997341,16024389,17309967,20268305,21721771,24771111,28429201,28741739 %N A161514 Number of digits in n-th even perfect number written in base 8. %C A161514 Or number of digits in A161323(n), assuming that all perfect numbers are even. %H A161514 Ivan Panchenko, <a href="/A161514/b161514.txt">Table of n, a(n) for n = 1..47</a> %Y A161514 Cf. A000396, A161323. %K A161514 nonn,base %O A161514 1,2 %A A161514 _Juri-Stepan Gerasimov_, Jun 12 2009 %E A161514 Definition changed (inserting the word "even"), a(12) and a(27) corrected and a(40)-a(45) added by _Ivan Panchenko_, Aug 06 2018