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 A321072 #19 Dec 05 2022 08:35:35
%S A321072 0,5,27,753,11401,26042,1475501,17419550,95368234,738444877,
%T A321072 21959974096,73834823298,2356328188186,11771613318349,149862461894073,
%U A321072 3567610964143242,7744859133558893,421292427905708342,1937633513403589655,18617385453880284098,18617385453880284098
%N A321072 One of the two successive approximations up to 11^n for 11-adic integer sqrt(3). Here the 5 (mod 11) case (except for n = 0).
%C A321072 For n > 0, a(n) is the unique solution to x^2 == 3 (mod 11^n) in the range [0, 11^n - 1] and congruent to 5 modulo 11.
%C A321072 Differs from A034946 since a(20). A034946 lists terms of this sequence without repetition.
%C A321072 A321073 is the approximation (congruent to 6 mod 11) of another square root of 3 over the 11-adic field.
%H A321072 Wikipedia, <a href="https://en.wikipedia.org/wiki/P-adic_number">p-adic number</a>
%F A321072 For n > 0, a(n) = 11^n - A321073(n).
%F A321072 a(n) = Sum_{i=0..n-1} A321074(i)*11^i.
%F A321072 a(n) == ((5 + sqrt(21))/2)^(11^n) + ((5 - sqrt(21))/2)^(11^n) (mod 11^n). - _Peter Bala_, Dec 04 2022
%e A321072 5^2 = 25 = 3 + 2*11.
%e A321072 27^2 = 729 = 3 + 6*11^2.
%e A321072 753^2 = 567009 = 3 + 426*11^3.
%o A321072 (PARI) a(n) = truncate(sqrt(3+O(11^n)))
%Y A321072 Cf. A034946, A321073, A321074.
%K A321072 nonn,easy
%O A321072 0,2
%A A321072 _Jianing Song_, Oct 27 2018