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 A249181 #20 Sep 08 2022 08:46:10
%S A249181 0,1,144,15129,1522756,152399025,15241383936,1524155677489,
%T A249181 152415765279684,15241578750190521,1524157875019052100,
%U A249181 152415787526596567801,15241578753153483936144,1524157875322755800955129,152415787532374345526722756,15241578753238669120562399025
%N A249181 a(n) = A057137(n)^2 where A057137 = 0,1,12,123,...,123...90,...
%C A249181 A very common playful operation on pocket calculators is to type as many digits 123... as the display allows and then squaring it by pressing the "X" and then the "=" key. On basic pocket calculators this yields an overflow with the first digits of, e.g., a(8) displayed, viz "E 1524157.6".
%H A249181 <a href="/index/Rec#order_21">Index entries for linear recurrences with constant coefficients</a>, signature (100, 0, 0, 0, 0, 0, 0, 0, 0, 10000000001, -1000000000100, 0, 0, 0, 0, 0, 0, 0, 0, -10000000000, 1000000000000).
%F A249181 For n<10, a(n) = A014824(n)^2 = floor(10^(n+1)/81-n/9)^2.
%F A249181 a(n) ~ 1.524157875...*10^(2n-2).
%e A249181 a(3) = 123^2 = 15129.
%e A249181 a(10) = 1234567890^2 = 1524157875019052100.
%o A249181 (PARI) print1(t=0);for(i=1,19,t=t*10+i%10;print1(","t*t))
%o A249181 (PARI) A249181(n)=(137174210*10^n\1111111111)^2
%o A249181 (Magma) [(137174210*10^n div 1111111111)^2: n in [0..20]]; // _Vincenzo Librandi_, Oct 23 2014
%K A249181 nonn,base
%O A249181 0,3
%A A249181 _M. F. Hasler_, Oct 22 2014