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Coefficients in asymptotic expansion of normal probability function.
7

%I #28 Nov 18 2023 08:27:27

%S 1,1,1,5,9,129,57,9141,-36879,1430049,-15439407,418019205,-7404957255,

%T 196896257505,-4656470025015,134136890777205,-3845524501226655,

%U 123250625100419265,-4085349586734306015,145973136800663973765

%N Coefficients in asymptotic expansion of normal probability function.

%C a(0) + a(1)*x/(1-2*x) + a(2)*x^2/((1-2*x)*(1-4*x)) + ... = 1 + x + 3*x^2 + 15*x^3 + ...

%D M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards Applied Math. Series 55, 1964 (and various reprintings), p. 932.

%H Vaclav Kotesovec, <a href="/A097397/b097397.txt">Table of n, a(n) for n = 0..200</a>

%H M. Abramowitz and I. A. Stegun, eds., <a href="http://www.convertit.com/Go/ConvertIt/Reference/AMS55.ASP">Handbook of Mathematical Functions</a>, National Bureau of Standards, Applied Math. Series 55, Tenth Printing, 1972 [alternative scanned copy].

%F E.g.f.: 1/sqrt(1 - log(1 + 2*x)). - _Seiichi Manyama_, Mar 05 2022

%F a(n) ~ n! * (-1)^(n+1) * 2^(n-1) / (log(n)^(3/2) * n) * (1 - 3*(gamma + 1)/(2*log(n)) + 15*(1 + 2*gamma + gamma^2 - Pi^2/6) / (8*log(n)^2)), where gamma is the Euler-Mascheroni constant A001620. - _Vaclav Kotesovec_, Mar 05 2022

%F From _Seiichi Manyama_, Nov 18 2023: (Start)

%F a(n) = Sum_{k=0..n} 2^(n-k) * (Product_{j=0..k-1} (2*j+1)) * Stirling1(n,k).

%F a(0) = 1; a(n) = Sum_{k=1..n} (-2)^k * (1/2 * k/n - 1) * (k-1)! * binomial(n,k) * a(n-k). (End)

%t Table[Sum[2^(n - 2*k)*(2*k)!/k! * SeriesCoefficient[(1 - n + x)*Pochhammer[2 - n + x, -1 + n], {x, 0, k}], {k, 0, n}], {n, 0, 20}] (* _Vaclav Kotesovec_, Aug 10 2019 *)

%o (PARI) a(n)=sum(k=0,n, 2^(n-2*k)*(2*k)!/k!* polcoeff(prod(i=0,n-1,x-i),k))

%o (PARI) my(N=20, x='x+O('x^N)); Vec(serlaplace(1/sqrt(1-log(1+2*x)))) \\ _Seiichi Manyama_, Mar 05 2022

%Y Cf. A006252, A352070, A352073.

%K sign

%O 0,4

%A _Michael Somos_, Aug 13 2004