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 A321397 #10 Dec 08 2018 11:50:21 %S A321397 0,1,0,1,1,3,3,10,10,32,37,105,131,364,464,1269,1690,4478,6163,16070, %T A321397 22582,58197,83431,212337,309890,780706,1155906,2888189,4331109, %U A321397 10739640,16291293,40123020,61483211,150518418,232754753,566704138,883597884,2140614523 %N A321397 a is the limit of A321396. %C A321397 The sequence a is the limit of the square array A321396 means, that for every fixed k the terms in column k of A321396 differ from a(k) only for finitely many indices. %t A321397 terms = 38; gf[-1] = 1; gf[n_] := gf[n] = (1-Sqrt[1-4z^2 gf[n -1]])/(2z); %t A321397 row[n_] := row[n] = gf[n]/z^n + O[z]^terms // CoefficientList[#, z]&; %t A321397 row[n = 1]; row[n++]; While[Print[n]; row[n] != row[n-1], n++]; %t A321397 A321397 = row[n] (* _Jean-François Alcover_, Dec 08 2018 *) %Y A321397 Cf. A321396. %K A321397 nonn %O A321397 0,6 %A A321397 _Peter Luschny_, Nov 11 2018