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 A242496 #29 Oct 03 2020 15:17:43 %S A242496 0,1,7,23,72,204,564,1521,4059,10747,28336,74504,195576,512865, %T A242496 1344063,3521007,9221688,24148468,63230860,165555665,433454835, %U A242496 1134839091,2971111392,7778574288,20364739632,53315851969,139583151799,365434146311,956720165544 %N A242496 a(n)=sum_{j=0..n} sum_{i=0..j} F(i)*L(j), where F(n)=A000045(n) and L(n)=A000032(n). %H A242496 Harvey P. Dale, <a href="/A242496/b242496.txt">Table of n, a(n) for n = 0..1000</a> %H A242496 <a href="/index/Rec#order_06">Index entries for linear recurrences with constant coefficients</a>, signature (4,-2,-6,4,2,-1). %F A242496 a(n) = A001519(n+2) - A000032(n+2) + A059841(n). %F A242496 a(n) = L(n)*F(n+3) - L(n+2) + (1-3*(-1)^n)/2. - _Colin Barker_, May 18 2014 %F A242496 G.f.: -x*(3*x^2-3*x-1) / ((x-1)*(x+1)*(x^2-3*x+1)*(x^2+x-1)). - _Colin Barker_, May 16 2014 %e A242496 For n=5, 0*(2+1+3+4+7+11) + 1*(1+3+4+7+11) + 1*(3+4+7+11) + 2*(4+7+11) + 3*(7+11) + 5*11 = 204 = F(2*5+3) - L(n+2) + 0 = 233-29 = 204. %p A242496 A242496 := proc(n) %p A242496 add(add(A000045(i)*A000032(j),i=0..j),j=0..n) ; %p A242496 end proc: # _R. J. Mathar_, May 17 2014 %t A242496 LinearRecurrence[{4,-2,-6,4,2,-1},{0,1,7,23,72,204},30] (* _Harvey P. Dale_, Oct 03 2020 *) %o A242496 (PARI) %o A242496 F(n) = fibonacci(n) %o A242496 L(n) = if(n==0, 2, F(2*n)/F(n)) %o A242496 vector(30, n, sum(i=0, n-1, sum(j=i, n-1, F(i)*L(j)))) \\ _Colin Barker_, May 16 2014 %Y A242496 Cf. A190173, A000045, A000032, A242300. %K A242496 nonn,easy %O A242496 0,3 %A A242496 _J. M. Bergot_, May 16 2014 %E A242496 Two terms corrected, and more terms added by _Colin Barker_, May 16 2014 %E A242496 Formula corrected by _Colin Barker_, May 17 2014