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 A334364 #16 Apr 05 2024 08:02:20
%S A334364 5,0,1,3,8,9,1,6,4,4,7,3,5,5,2,0,3,0,5,3,8,4,8,4,5,0,6,6,5,7,0,4,2,5,
%T A334364 3,9,4,3,4,6,0,9,3,4,5,8,7,3,9,7,0,7,3,8,5,3,3,6,5,2,4,7,9,6,6,4,8,3,
%U A334364 4,3,3,4,1,3,7,3,7,5,9,6,7,2,2,3,1,5,6,4,3,5,1,7,4,1,7,9,9,7,3,1,2,1,7,3,7,5,6,3,7,2
%N A334364 Decimal expansion of Sum_{k>=0} 1/(4*k+2)!.
%H A334364 Michael I. Shamos, <a href="http://euro.ecom.cmu.edu/people/faculty/mshamos/cat.pdf">A catalog of the real numbers</a>, (2011). See p. 457.
%F A334364 Equals (cosh(1) - cos(1))/2.
%e A334364 1/2! + 1/6! + 1/10! + ... = 0.5013891644735520305...
%t A334364 RealDigits[(Cosh[1] - Cos[1])/2, 10, 110] [[1]]
%o A334364 (PARI) suminf(k=0, 1/(4*k+2)!) \\ _Michel Marcus_, Apr 25 2020
%Y A334364 Cf. A001113, A049470, A073743, A143821, A332890, A334363, A334365.
%K A334364 nonn,cons
%O A334364 0,1
%A A334364 _Ilya Gutkovskiy_, Apr 24 2020