cp's OEIS Frontend

A369881 Decimal expansion of 1/(2*sqrt(e)).

%I A369881 #8 Apr 26 2025 20:54:43
%S A369881 3,0,3,2,6,5,3,2,9,8,5,6,3,1,6,7,1,1,8,0,1,8,9,9,7,6,7,4,9,5,5,9,0,2,
%T A369881 2,6,7,2,0,9,5,9,0,6,7,7,4,3,5,9,3,4,7,7,8,4,1,4,4,6,0,7,9,3,6,7,5,2,
%U A369881 8,2,5,9,7,0,6,8,7,4,2,1,1,9,9,9,3,2,3,8,0,5,7,5,3,9,9,4,7,2,8,0,1,3,2,1,1
%N A369881 Decimal expansion of 1/(2*sqrt(e)).
%H A369881 D. M. Batinetu-Giurgiu, <a href="https://www.kappamuepsilon.org/Pentagon/Vol_75_Num_2_Spring_2016.pdf">Problem 764</a>, The Pentagon, Vol. 75, No. 2 (2016), p. 22.
%H A369881 Toyesh Prakash Sharma, <a href="https://www.mateinfo.ro/reviste-de-matematica/revista-electronica-de-matematica-mateinfo-ro-aparitie-lunara-2065-6432/revista-mateinfo-ro/revista-electronica-mateinfo-ro-2020/1157-revista-electronica-mateinfo-ro-decembrie-2020">The Applications of the Stirling's approximation to find limits</a>, Revista Electronica MateInfo.ro, December 2020, pp. 44-49. See Problem 13, p. 49.
%F A369881 Equals A092605 / 2.
%F A369881 Equals exp(-(1 + A187832)).
%F A369881 Equals Sum_{n>=1} (-1)^(n+1)/A066318(n).
%F A369881 Equals lim_{n->oo} sqrt(n)*(((n+1)!)^(1/(2*(n+1))) - (n!)^(1/(2*n))) (Batinetu-Giurgiu, 2016).
%e A369881 0.30326532985631671180189976749559022672095906774359...
%t A369881 RealDigits[1/(2*Sqrt[E]), 10, 105][[1]]
%o A369881 (PARI) exp(-1/2)/2
%Y A369881 Cf. A001113, A019774, A019778, A066318, A092605, A187832, A249455.
%K A369881 nonn,cons,easy
%O A369881 0,1
%A A369881 _Amiram Eldar_, Feb 04 2024