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 A375804 #12 Jan 05 2025 19:51:42
%S A375804 12,40,1365,19448,381276,6615103,120241980,2147070680,38600066517,
%T A375804 692153278024,12423591148332,222908960952575,4000098954110700,
%U A375804 71777766990248968,1288007282149222101,23112301389881302808,414733773612913239420,7442093184423393874495,133542960264663589170972
%N A375804 a(n) = Lucas(n-1) * Lucas(n+1) * Fibonacci(2*n-1) * Fibonacci(2*n+1).
%H A375804 Amiram Eldar, <a href="/A375804/b375804.txt">Table of n, a(n) for n = 1..798</a>
%H A375804 Hideyuki Ohtskua, proposer, <a href="https://web.archive.org/web/2024*/https://www.fq.math.ca/Problems/AugAdvProb2024.pdf">Problem H-944</a>, Advanced Problems and Solutions, The Fibonacci Quarterly, Vol. 62, No. 3 (2024), p. 266.
%H A375804 <a href="/index/Rec#order_07">Index entries for linear recurrences with constant coefficients</a>, signature (13,104,-260,-260,104,13,-1).
%F A375804 a(n) = A292696(n) * A064170(n+2).
%F A375804 Sum_{n>=1} (-1)^(n+1)/a(n) = (sqrt(5) - 2)/ 4 = A204188 - 1/2 (Ohtskua, 2024).
%F A375804 G.f.: -x^2*(-20+65*x+195*x^2-84*x^3-13*x^4+x^5)/ ( (1+x) *(x^2-3*x+1) *(x^2+7*x+1) *(x^2-18*x+1) ). - _R. J. Mathar_, Aug 30 2024
%t A375804 a[n_] := LucasL[n-1] * LucasL[n+1] * Fibonacci[2*n-1] * Fibonacci[2*n+1]; Array[a, 20]
%o A375804 (PARI) lucas(n) = fibonacci(n-1) + fibonacci(n+1);
%o A375804 a(n) = lucas(n-1) * lucas(n+1) * fibonacci(2*n-1) * fibonacci(2*n+1);
%Y A375804 Cf. A000032, A000045, A064170, A204188, A292696, A375803.
%K A375804 nonn,easy
%O A375804 1,1
%A A375804 _Amiram Eldar_, Aug 29 2024