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 A111649 #36 Feb 06 2024 10:17:45
%S A111649 3,71,2379,80783,2744211,93222359,3166815963,107578520351,
%T A111649 3654502875939,124145519261543,4217293152016491,143263821649299119,
%U A111649 4866752642924153523,165326326037771920631,5616228332641321147899
%N A111649 a(n) = A001541(n)*A001653(n+1) + A001541(n)*A002315(n) + A001653(n+1)*A002315(n).
%H A111649 Ray Chandler, <a href="/A111649/b111649.txt">Table of n, a(n) for n = 0..652</a>
%H A111649 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (35,-35,1).
%F A111649 a(n) = A001653(2n+2) - 2*A002315(n)^2, e.g., 2379 = 5741 - 2*41^2;
%F A111649 a(n) = A001652(2n) + A002315(n)^2 + 2, e.g., 2379 = 696 + 41^2 + 2;
%F A111649 a(n) = 2*A046176(n+1)+1, e.g., 2379 = 2*1189 + 1.
%F A111649 G.f.: (x^2+34*x-3) / ((x-1)*(x^2-34*x+1)). - _Colin Barker_, Dec 14 2014 [adjusted for corrected term and empirical g.f. confirmed for more terms and recurrence of source sequences. - _Ray Chandler_, Feb 05 2024]
%e A111649 a(1) = 71 = 3*5 + 3*7 + 5*7.
%t A111649 LinearRecurrence[{35, -35, 1}, {3, 71, 2379}, 20] (* _Paolo Xausa_, Feb 06 2024 *)
%Y A111649 Cf. A001541, A001653, A002315, A111647, A111648.
%K A111649 nonn
%O A111649 0,1
%A A111649 _Charlie Marion_, Aug 24 2005
%E A111649 a(3) = 80783 corrected by _Ray Chandler_, Feb 05 2024