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 A144927 #21 Jul 05 2024 10:43:11
%S A144927 7,1162,128191,14100226,1550897047,170584575322,18762752388751,
%T A144927 2063732178187666,226991776848254887,24967031721129850282,
%U A144927 2746146497547435276511,302051147698496750566306,33222880100337095127017527,3654214759889381967221362042
%N A144927 Numbers n such that there exists an integer k with (n+7)^3-n^3=k^2.
%H A144927 Colin Barker, <a href="/A144927/b144927.txt">Table of n, a(n) for n = 1..450</a>
%H A144927 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (111,-111,1).
%F A144927 a(n+2) = 110*a(n+1) - a(n) + 378.
%F A144927 G.f.: 7*x*(-1-55*x+2*x^2) / ( (x-1)*(x^2-110*x+1) ). - _R. J. Mathar_, Nov 27 2011
%F A144927 a(n) = 7*A144929(n). - _R. J. Mathar_, Nov 27 2011
%e A144927 a(1)=7 because 14^3-7^3=49^2.
%t A144927 Last /@ Table[n /. {ToRules[Reduce[n > 0 && k >= 0 && (n + 7)^3 - n^3 == k^2, n, Integers] /. C[1] -> c]} // Simplify, {c, 1, 14}] (* or *)
%t A144927 Rest@ CoefficientList[Series[7 x (-1 - 55 x + 2 x^2)/((x - 1) (x^2 - 110 x + 1)), {x, 0, 14}], x] (* _Michael De Vlieger_, Jul 14 2016 *)
%t A144927 LinearRecurrence[{111,-111,1},{7,1162,128191},20] (* _Harvey P. Dale_, Jul 05 2024 *)
%o A144927 (PARI) Vec(7*x*(-1-55*x+2*x^2)/((x-1)*(x^2-110*x+1)) + O(x^20)) \\ _Colin Barker_, Jul 14 2016
%Y A144927 Cf. A144928, A144930, A144929.
%K A144927 easy,nonn
%O A144927 1,1
%A A144927 _Richard Choulet_, Sep 25 2008