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 A263945 #7 Mar 25 2020 16:49:44
%S A263945 26,871,59930,1155895,77814386,1500376111,101003038370,1947487061455,
%T A263945 131101866015146,2527836705417751,170170121084646410,
%U A263945 3281130096145204615,220880686066005050306,4258904336959770197791,286702960343553470676050,5528054548243685571553375
%N A263945 Positive integers n such that (n+39)^3 - n^3 is a square.
%H A263945 Colin Barker, <a href="/A263945/b263945.txt">Table of n, a(n) for n = 1..642</a>
%H A263945 <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (1,1298,-1298,-1,1).
%F A263945 a(n) = a(n-1)+1298*a(n-2)-1298*a(n-3)-a(n-4)+a(n-5) for n>5.
%F A263945 G.f.: 13*x*(5*x^4+65*x^3-1947*x^2-65*x-2) / ((x-1)*(x^2-36*x-1)*(x^2+36*x-1)).
%e A263945 26 is in the sequence because (26+39)^3 - 26^3 = 507^2.
%t A263945 LinearRecurrence[{1,1298,-1298,-1,1},{26,871,59930,1155895,77814386},20] (* _Harvey P. Dale_, Mar 25 2020 *)
%o A263945 (PARI) Vec(13*x*(5*x^4+65*x^3-1947*x^2-65*x-2)/((x-1)*(x^2-36*x-1)*(x^2+36*x-1)) + O(x^30))
%Y A263945 Cf. A263942 (4), A263943 (21), A263944 (28), A263946 (52), A263947 (57), A263948 (61), A263949 (84) where the parenthesized number is k in the expression (n+k)^3 - n^3.
%K A263945 nonn,easy
%O A263945 1,1
%A A263945 _Colin Barker_, Oct 30 2015