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 A321595 #10 Nov 15 2018 03:37:32
%S A321595 2,8,0,5,0,4,1,4,1,7,2,5,6,5,9,8,7,8,7,7,6,8,8,7,9,4,3,1,6,3,9,9,3,3,
%T A321595 1,7,5,8,8,5,9,6,0,4,2,3,7,5,2,6,5,9,3,9,6,5,8,2,7,8,7,0,2,7,7,8,3,8,
%U A321595 8,3,0,4,9,1,8,2,0,4,4,8,3,9,4,6,1,6,8,7
%N A321595 Decimal expansion of the sum of the reciprocal of the Genocchi numbers (of first kind) with even index (negated).
%C A321595 If also the reciprocal of G(1) = 1 is added we get .7194958582743401212231...
%F A321595 Equals Sum_{k>0} 1/A036968(2*k).
%e A321595 -.28050414170674716801892095479922438557021976395598927505615374848326107452...
%p A321595 with(numtheory): P:=proc(h) local a,x,k,n; a:=[seq(factorial(n)*coeff(series(2*x/(1+exp(x)),x=0,h+1),x,n),n=1..h)]; print(evalf(add(1/a[2*k],k=1..trunc(h/2)),200)); end: P(300);
%Y A321595 Cf. A036968, A300220.
%K A321595 nonn,cons,easy
%O A321595 0,1
%A A321595 _Paolo P. Lava_, Nov 14 2018