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 A180053 #30 Jul 29 2024 13:11:04
%S A180053 1,101,101101,101202101,101303303101,101404606404101,
%T A180053 101506011010505101,101607517021515606101,101709124538537121707101,
%U A180053 101810833663075658828808101,101912644496738734487636909101,102014557141235473222124546010101
%N A180053 a(1)=1, a(2)=101, a(n) = 1001*a(n-1) for n > 2.
%H A180053 <a href="/index/Rec#order_01">Index entries for linear recurrences with constant coefficients</a>, signature (1001).
%F A180053 G.f.: x(1-900*x)/(1-1001*x). - _Philippe Deléham_, Oct 08 2011
%e A180053 In a column:
%e A180053 1
%e A180053 101
%e A180053 101101
%e A180053 101202101
%e A180053 101303303101
%e A180053 101404606404101
%t A180053 LinearRecurrence[{1001}, {1, 101}, 15] (* _Paolo Xausa_, Jan 29 2024 *)
%t A180053 Join[{1},NestList[1001#&,101,10]] (* _Harvey P. Dale_, Jul 29 2024 *)
%o A180053 (PARI) a(n)=max(101*1001^(n-2),1) \\ _Charles R Greathouse IV_, Oct 08 2011
%Y A180053 Cf. A093645.
%K A180053 nonn,easy
%O A180053 1,2
%A A180053 _Mark Dols_, Aug 08 2010