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 A047137 #11 Jan 20 2020 10:14:27 %S A047137 1,3,9,28,104,367,1295,4600,17229,64069,238148,886823,3366045, %T A047137 12793452,48663267,185303586,711046282,2734845898,10532016662, %U A047137 40599379289,157049408777,608667818351,2361851906708,9173261457282 %N A047137 a(n) = T(n,n+2), array T as in A047130. %Y A047137 Cf. A047130. %K A047137 nonn %O A047137 0,2 %A A047137 _Clark Kimberling_ %E A047137 Definition corrected by _Georg Fischer_, Jan 20 2020