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A367549 Decimal expansion of 1 - DawsonF(1/2).

%I A367549 #14 Jun 06 2025 08:36:51
%S A367549 5,7,5,5,6,3,6,1,6,4,9,7,9,7,7,7,0,4,0,6,5,9,5,7,6,4,7,5,1,0,3,3,0,4,
%T A367549 2,8,9,0,3,5,7,0,5,2,2,6,4,0,3,0,7,9,6,1,8,4,8,6,6,0,3,0,3,3,6,6,7,5,
%U A367549 4,8,4,5,2,4,0,4,0,8,0,5,2,3,8,3,2,2,8,7,9,8,7,1,5,2,1,3,8,7,7,7,8,5,7,4,0,3,8,3,0,2
%N A367549 Decimal expansion of 1 - DawsonF(1/2).
%H A367549 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/DawsonsIntegral.html">Dawson's Integral</a>.
%F A367549 Equals 1 - sqrt(Pi/4) * erfi(1/2) / exp(1/4) = 1 - A019704 * A367563 / A092042.
%F A367549 Let C denote the constant. Then:
%F A367549 2*C - 1 = Sum_{n>=0} (-1)^n / Pochhammer(n, n).
%F A367549 2*(C - 1) = Sum_{n>=1} (-1)^n*Gamma(n) / Gamma(2*n).
%F A367549 Equals Integral_{x=0..oo} exp(-x)*cos(sqrt(x)) dx. - _Kritsada Moomuang_, Jun 06 2025
%e A367549 0.57556361649797770406595764751033042890357052264030796184866030336675484524040...
%p A367549 1 - sqrt(Pi/4)*erfi(1/2)/exp(1/4): evalf(%, 109);
%t A367549 N[1 - DawsonF[1/2], 110] // RealDigits // First
%Y A367549 Cf. A019704, A092042, A367563.
%K A367549 nonn,cons
%O A367549 0,1
%A A367549 _Peter Luschny_, Nov 23 2023