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 A061748 #5 Dec 05 2013 19:54:51 %S A061748 1,9,17,915,17913,91517911,179139151799,91517911179139151717, %T A061748 1791391517999151791117913915915, %U A061748 91517911179139151717179139151799915179111791317913 %N A061748 a(0) = 1; a(n) is obtained by incrementing each digit of a(n-1) by 8. %C A061748 In A061511-A061522, A061746-A061750 when the incremented digit exceeds 9 it is written as a 2-digit string. So 9+1 becomes the 2-digit string 10, etc. %t A061748 NestList[FromDigits[Flatten[IntegerDigits/@(IntegerDigits[#]+8)]]&,1,10] (* _Harvey P. Dale_, Aug 20 2012 *) %K A061748 base,nonn %O A061748 0,2 %A A061748 _Amarnath Murthy_, May 08 2001 %E A061748 More terms from Larry Reeves (larryr(AT)acm.org), May 11 2001