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A117437 E.g.f. exp(x)sec(2x). 2
1, 1, 5, 13, 105, 441, 5165, 30213, 469585, 3529201, 68525525, 629401213, 14664091065, 159175688361, 4326609913085, 54189700721013, 1683369010256545, 23894940183997921, 835066388382183845, 13248060325188261613 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

Row sums of A117436. Binomial transform of A002436 (with interpolated zeros).

LINKS

Table of n, a(n) for n=0..19.

FORMULA

a(n) ~ n! * 2^(2*n+1) * (exp(Pi/4) + (-1)^n*exp(-Pi/4)) / Pi^(n+1). - Vaclav Kotesovec, Aug 04 2014

MATHEMATICA

With[{nn=30}, CoefficientList[Series[Exp[x]Sec[2x], {x, 0, nn}], x] Range[0, nn]!] (* Harvey P. Dale, Dec 13 2011 *)

CROSSREFS

Sequence in context: A304348 A305912 A180827 * A179089 A106046 A180362

Adjacent sequences:  A117434 A117435 A117436 * A117438 A117439 A117440

KEYWORD

easy,nonn

AUTHOR

Paul Barry, Mar 16 2006

STATUS

approved

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Last modified August 17 15:36 EDT 2018. Contains 313816 sequences. (Running on oeis4.)