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 A204327 #15 May 08 2025 03:36:01
%S A204327 1,12,985,470832,1311738121,21300003689580,2015874949414289041,
%T A204327 1111984844349868137938112,3575077977948634627394046618865,
%U A204327 66992092050551637663438906713182313772,7316660981177400006023755031791634132229378601
%N A204327 a(n) = Pell(n^2).
%H A204327 Seiichi Manyama, <a href="/A204327/b204327.txt">Table of n, a(n) for n = 1..51</a>
%F A204327 a(n) = ( (1+sqrt(2))^(n^2) - (1-sqrt(2))^(n^2) ) / (2*sqrt(2)).
%e A204327 G.f.: A(x) = x + 12*x^2 + 985*x^3 + 470832*x^4 + 1311738121*x^5 +...
%o A204327 (PARI) {Pell(n)=polcoeff(x/(1-2*x-x^2+x*O(x^n)), n)}
%o A204327 {a(n)=Pell(n^2)}
%Y A204327 Cf. A000129 (Pell), A000290 (n^2), A204274, A165938, A165937, A166879, A054783.
%K A204327 nonn
%O A204327 1,2
%A A204327 _Paul D. Hanna_, Jan 14 2012