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 A292227 #13 Oct 30 2017 18:01:09
%S A292227 1,7,93,467,19173,1170203,19898781,2248887383,65223261317,
%T A292227 11806034873107,694496744821,625756401440091,195865032043506253,
%U A292227 14298321093992118279,6019647565828140441989,222728486906331381429243,24277533643722234159157217,14882189966220076173164214151
%N A292227 Numerators of partial sums of the series 1 + 2*Sum_{k >= 1} 1/(4*k^4 + 1).
%C A292227 The corresponding denominators are given in A292228.
%C A292227 The value of the series 1 + 2*Sum_{k >= 1} 1/(4*k^4 +1) is (Pi/2)*tanh(Pi/2) given in A228048. See the Koecher reference, p. 189.
%D A292227 Max Koecher, Klassische elementare Analysis, Birkhäuser, Basel, Boston, 1987, p. 189.
%H A292227 Robert Israel, <a href="/A292227/b292227.txt">Table of n, a(n) for n = 0..340</a>
%F A292227 a(n) = numerators(s(n)) with the rationals (in lowest terms) s(n) = 1 + 2*Sum_{k=1..n} 1/(4*k^4 + 1), n >= 0.
%e A292227 The rationals s(n) begin: 1, 7/5, 93/65, 467/325, 19173/13325, 1170203/812825, 19898781/13818025, 2248887383/1561436825,...
%e A292227 s(10^5) = 1.4406595199775144260 (Maple 20 digits), to be compared with 1.4406595199775145926 (20 digits from A228048).
%p A292227 seq(numer(t),t=ListTools:-PartialSums([1, seq(2/(4*k^4+1),k=1..30)]));
%t A292227 {1}~Join~Numerator[1 + 2 Accumulate[Array[1/(4 #^4 + 1) &, 17]]] (* _Michael De Vlieger_, Oct 30 2017 *)
%o A292227 (PARI) a(n) = numerator(1+2*sum(k=1, n, 1/(4*k^4 + 1))); \\ _Michel Marcus_, Oct 30 2017
%Y A292227 Cf. A228048, A292228.
%K A292227 nonn,frac,easy
%O A292227 0,2
%A A292227 _Wolfdieter Lang_, Oct 30 2017