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 A203797 #13 Aug 18 2023 05:24:12
%S A203797 1,3,6,19,30,120,170,647,1183,3650,5742,24916,33462,121652,240756,
%T A203797 746639,1136690,4707147,6625110,25882770,46565244,139849776,225058682,
%U A203797 978088748,1356970471,4750318586,9182205852,29333908544,44560482150,188175715440,259717522850,994309609247
%N A203797 a(n) = Pell(n) * Sum_{d|n} 1/Pell(d), where Pell(n) = A000129(n).
%F A203797 G.f.: Sum_{n>=1} x^n/(1 - A002203(n)*x^n + (-1)^n*x^(2*n)), where A002203 is the companion Pell numbers.
%e A203797 G.f.: A(x) = x + 3*x^2 + 6*x^3 + 19*x^4 + 30*x^5 + 120*x^6 + 170*x^7 + ... where A(x) = x/(1-2*x-x^2) + x^2/(1-6*x^2+x^4) + x^3/(1-14*x^3-x^6) + x^4/(1-34*x^4+x^8) + x^5/(1-82*x^5-x^10) + x^6/(1-198*x^6+x^12) + ... + x^n/(1 - A002203(n)*x^n + (-1)^n*x^(2*n)) + ...
%t A203797 a[n_] := Fibonacci[n, 2] * DivisorSum[n, 1/Fibonacci[#, 2] &]; Array[a, 32] (* _Amiram Eldar_, Aug 18 2023 *)
%o A203797 (PARI) {Pell(n)=polcoeff(x/(1-2*x-x^2+x*O(x^n)),n)}
%o A203797 {a(n)=Pell(n) * sumdiv(n, d, 1/Pell(d))}
%o A203797 (PARI) /* G.f. using companion Pell numbers: */
%o A203797 {A002203(n)=polcoeff(2*(1-x)/(1-2*x-x^2+x*O(x^n)),n)}
%o A203797 {a(n)=polcoeff(sum(m=1, n, x^m/(1 - A002203(m)*x^m + (-1)^m*x^(2*m) +x*O(x^n))), n)}
%Y A203797 Cf. A204059, A111075, A203802, A000129, A002203.
%K A203797 nonn
%O A203797 1,2
%A A203797 _Paul D. Hanna_, Jan 13 2012