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 A211182 E.g.f. 1-x*(1-x)*(tan(x)+sec(x)). 1

%I

%S 1,-1,0,3,4,15,54,245,1240,7119,45290,317229,2423268,20055607,

%T 178747646,1706919045,17386518448,188166282399,2156226542802,

%U 26081233464413,332076574410940,4439536794401415,62178531797006438,910433903838620853,13910405388847664904

%N E.g.f. 1-x*(1-x)*(tan(x)+sec(x)).

%H Vincenzo Librandi, <a href="/A211182/b211182.txt">Table of n, a(n) for n = 0..202</a>

%F a(n) ~ n! * (Pi-2)*2^n/Pi^n. - _Vaclav Kotesovec_, Feb 12 2013

%t With[{nn = 24}, CoefficientList[ Series[1 - x (1 - x) (Tan[x] + Sec[x]), {x, 0, nn}], x] Range[0, nn]!]

%t Join[{1, -1, 0}, Table[-n * (((n-1)*EulerE[n-2] + 2^(n-1)*EulerE[n-1, 0]) * Cos[Pi*n/2] + (EulerE[n-1] - 2^(n-2)*(n-1)*EulerE[n-2, 0]) * Sin[Pi*n/2]), {n, 3, 30}]] (* _Benedict W. J. Irwin_, Jul 28 2016 *)

%Y Cf. A034428.

%K sign,easy

%O 0,4

%A LtC. R. Scott Patterson (aa737drvr(AT)comcast.net) and _Robert G. Wilson v_, Feb 02 2013

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Last modified September 26 16:43 EDT 2020. Contains 337374 sequences. (Running on oeis4.)