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A134378 A084938 * [1,2,3,...], where A084938 = the Delta operator. 4
1, 2, 5, 14, 44, 158, 663, 3310, 19759, 139660, 1147120, 10729684, 112309193, 1297522650, 16371057801, 223716758346, 3289199827236, 51745234494858, 867023125576027, 15411557297930534, 289610871340870883, 5736017561257017128, 119413599371241577016 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Alois P. Heinz, Table of n, a(n) for n = 0..170

FORMULA

a(n) ~ 2 * (n-1)! * (1 + 3/n + 12/n^2 + 58/n^3 + 327/n^4 + 2107/n^5 + 15329/n^6 + 125041/n^7 + 1139467/n^8 + 11582187/n^9 + 131230827/n^10). - Vaclav Kotesovec, Mar 17 2015

EXAMPLE

a(4) = 44 = (0, 6, 5, 3, 1) dot (1, 2, 3, 4, 5) = (0 + 12 + 15 + 12 + 5).

MAPLE

series((1-x*hypergeom([1, 1], [], x))^(-2), x=0, 50);  # appears to generate the sequence - Mark van Hoeij, Apr 22 2013

MATHEMATICA

CoefficientList[Series[1/(1-x*HypergeometricPFQ[{1, 1}, {}, x])^2, {x, 0, 20}], x] (* Vaclav Kotesovec, Mar 17 2015 after Mark van Hoeij *)

CoefficientList[Assuming[Element[x, Reals], Series[E^(2/x)/(ExpIntegralEi[1/x]-E^(1/x))^2, {x, 0, 25}]], x] (* Vaclav Kotesovec, Aug 03 2015 *)

CROSSREFS

Cf. A084938, A260532.

Sequence in context: A014322 A095148 A060996 * A101226 A240610 A149887

Adjacent sequences:  A134375 A134376 A134377 * A134379 A134380 A134381

KEYWORD

nonn

AUTHOR

Gary W. Adamson, Oct 22 2007, corrected Oct 26 2007

EXTENSIONS

More terms from Alois P. Heinz, Apr 27 2012

STATUS

approved

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Last modified April 20 09:59 EDT 2019. Contains 322309 sequences. (Running on oeis4.)