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 A055149 #8 Oct 27 2019 00:13:24
%S A055149 1,10,83,668,5349,42798,342391,2739129,21913032,175304257,1402434057,
%T A055149 11219472457,89755779658,718046237265,5744369898123,45954959184985,
%U A055149 367639673479884,2941117387839073,23528939102712589,188231512821700713
%N A055149 The first n digits of the juxtaposition of the base-8 numbers converted to decimal.
%e A055149 1 (1); 12 (10); 123 (83); 1234 (668); 12345 (5349); 123456 (42798); ...
%t A055149 nn=30;With[{b8=Flatten[IntegerDigits[Range[nn],8]]},Table[ FromDigits[ Take[ b8,n],8],{n,nn}]] (* _Harvey P. Dale_, Jul 12 2014 *)
%Y A055149 Cf. A054634, A054636, A055062, A055063, A055143-A055150.
%K A055149 nonn,base
%O A055149 1,2
%A A055149 _Patrick De Geest_, Apr 15 2000