cp's OEIS Frontend

A387268 Decimal expansion of Sum_{k>=0} (-1)^k/(k!)!.

%I A387268 #19 Aug 27 2025 01:09:45
%S A387268 4,9,8,6,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,7,2,2,8,4,8,6,8,2,2,
%T A387268 0,7,2,2,9,4,6,0,1,5,9,8,2,4,4,1,5,9,1,2,2,8,2,9,1,2,4,3,5,8,3,7,2,1,
%U A387268 3,7,1,8,3,3,9,0,8,4,6,4,0,4,0,1,1,4,2,1,2,1,5,6,1,6,5,9,6,3,7,9
%N A387268 Decimal expansion of Sum_{k>=0} (-1)^k/(k!)!.
%C A387268 This constant has an interesting simple continued fraction representation.
%C A387268 359/720 approximates this constant to 19 significant digits.
%H A387268 Daniel Hoyt, <a href="/A387268/b387268.txt">Table of n, a(n) for n = 0..999</a>
%e A387268 0.498611111111111111127228486822072294...
%t A387268 RealDigits[Sum[(-1)^k/(k!)!, {k, 0, 6}], 10, 100][[1]]
%o A387268 (PARI) suminf(k=0, (-1)^k/(k!)!)
%Y A387268 Cf. A386384 (continued fraction expansion).
%Y A387268 Cf. A363842, A336810.
%K A387268 nonn,cons,new
%O A387268 0,1
%A A387268 _Daniel Hoyt_, Aug 24 2025