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 A053369 #11 Sep 08 2022 08:45:00
%S A053369 2,9,32,115,420,1554,5808,21879,82940,316030,1209312,4644094,17889032,
%T A053369 69089700,267444000,1037348415,4030774380,15687019590,61137753600,
%U A053369 238580530650,932105099640,3645473785980,14271279927840,55918717024950,219283705045080,860564513057004,3379592965275968
%N A053369 Linear recursion with Catalan numbers.
%D A053369 A. H. Beiler, Recreations in the Theory of Numbers, Dover, N.Y., 1964, pp. 194-196.
%H A053369 G. C. Greubel, <a href="/A053369/b053369.txt">Table of n, a(n) for n = 0..1000</a>
%F A053369 a(n) = (7n+2)*C(n) where C(n)=Catalan numbers (A000108).
%t A053369 Table[(7*n + 2)*CatalanNumber[n], {n, 0, 50}] (* _G. C. Greubel_, May 25 2018 *)
%o A053369 (PARI) for(n=0,30, print1(((7*n+2)/(n+1))*binomial(2*n,n), ", ")) \\ _G. C. Greubel_, May 25 2018
%o A053369 (Magma) [((7*n+2)/(n+1))*Binomial(2*n,n): n in [0..30]]; // _G. C. Greubel_, May 25 2018
%Y A053369 Cf. A050960.
%K A053369 easy,nonn
%O A053369 0,1
%A A053369 _Barry E. Williams_, Jan 06 2000
%E A053369 Terms a(21) onward added by _G. C. Greubel_, May 25 2018