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A119882 E.g.f.: (1+x)*sech(x). 1
1, 1, -1, -3, 5, 25, -61, -427, 1385, 12465, -50521, -555731, 2702765, 35135945, -199360981, -2990414715, 19391512145, 329655706465, -2404879675441, -45692713833379, 370371188237525, 7777794952988025, -69348874393137901, -1595024111042171723, 15514534163557086905 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,4

COMMENTS

Transform of binomial(1,n) under the matrix A119879.

LINKS

Robert Israel, Table of n, a(n) for n = 0..480

FORMULA

a(n) = Sum_{k=0..n} A119879(n,k)*C(1,k).

E.g.f.: (1+x)/sech(x)=(1+x)*(1 - x^2/Q(0)), where Q(k) = (2*k+1)*(2*k+2) + x^2 - (2*k+1)*(2*k+2)*x^2/Q(k+1) ; (continued fraction). - Sergei N. Gladkovskii, Dec 06 2013

a(n) = EulerE[n] + n*EulerE[n-1], n>0. - Benedict W. J. Irwin, May 30 2016

MAPLE

seq(`if`(n::odd, n*euler(n-1), euler(n)), n=0..24); # Peter Luschny, May 30 2016

MATHEMATICA

Table[ EulerE[n] + n*EulerE[n - 1], {n, 1, 20}] (* Benedict W. J. Irwin, May 30 2016 *)

PROG

(PARI) Vec(serlaplace((1+x)/cosh(x + O(x^30)))) \\ Andrew Howroyd, Feb 27 2018

CROSSREFS

Cf. A119879, A122045.

Sequence in context: A208800 A249935 A009002 * A276968 A074701 A318179

Adjacent sequences:  A119879 A119880 A119881 * A119883 A119884 A119885

KEYWORD

easy,sign

AUTHOR

Paul Barry, May 26 2006

STATUS

approved

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Last modified November 21 01:33 EST 2019. Contains 329349 sequences. (Running on oeis4.)