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 A368049 #24 Jan 16 2024 11:08:11 %S A368049 16,25,36,49,64,81,100,121,144,225,400,441,484,676,900,1444,10000, %T A368049 40000,44944,90000,1000000,4000000,9000000,100000000,400000000, %U A368049 900000000,10000000000,40000000000,90000000000,1000000000000,4000000000000,9000000000000,100000000000000 %N A368049 Perfect squares whose decimal expansion consists of k > 1 digits, k-1 of which are equal. %C A368049 The terms > 90000 are of one of the following three forms: 10^(2*j), 4*10^(2*j) or 9*10^(2*j) where j is an integer >= 3. %C A368049 See Gica/Panaitopol link for proof of above comment. - _Ray Chandler_, Jan 16 2024 %H A368049 Ray Chandler, <a href="/A368049/b368049.txt">Table of n, a(n) for n = 1..1000</a> %H A368049 Alexandru Gica and Laurențiu Panaitopol, <a href="http://www.cs.uwaterloo.ca/journals/JIS/VOL6/Panaitopol/panaitopol41.html">On Oblath's Problem</a>, J. Integer Seq., Vol. 6 (2003), article 03.3.5, 12 pp. %H A368049 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,100). %F A368049 a(n) = 100*a(n-3) for n > 22. - _Stefano Spezia_, Dec 09 2023 %Y A368049 Cf. A235717, A018885. %Y A368049 Subsequence of A000290. %K A368049 nonn,base,easy %O A368049 1,1 %A A368049 _José Hernández_, Dec 09 2023