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 A356761 #12 Jan 05 2025 19:51:42
%S A356761 10,21,65,890,40446,33424885,1322190707485,44140596372269298846,
%T A356761 58360810951947188228658239895890,
%U A356761 2576080923024092500207469693559464507701547824744865,150342171745412969401059031474740559845525757221446054521410222913066501974929718621
%N A356761 a(n) = L(2*L(n)) + L(2*L(n+1)), where L(n) is the n-th Lucas number (A000032).
%H A356761 Amiram Eldar, <a href="/A356761/b356761.txt">Table of n, a(n) for n = 0..15</a>
%H A356761 Hideyuki Ohtsuka, <a href="https://web.archive.org/web/2024*/https://www.fq.math.ca/Problems/AdvProbAug2022.pdf">Problem H-901</a>, Advanced Problems and Solutions, The Fibonacci Quarterly, Vol. 60, No. 3 (2022), p. 281.
%F A356761 a(n) = A000032(2*A000032(n)) + A000032(2*A000032(n+1)).
%F A356761 Sum_{n>=0} (-1)^n/a(n) = 1/15 (Ohtsuka, 2022).
%t A356761 a[n_] := LucasL[2*LucasL[n]] + LucasL[2*LucasL[n + 1]]; Array[a, 11, 0]
%Y A356761 Cf. A000032, A356760.
%K A356761 nonn
%O A356761 0,1
%A A356761 _Amiram Eldar_, Aug 26 2022