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A305555 Sum of the areas of all L-elevated skew paths of semi-length n. 0
0, 0, 3, 19, 106, 564, 2935, 15091, 77037, 391433, 1982573, 10018605, 50541372, 254637294, 1281605541, 6445146105, 32390909850, 162695554860, 816825463045, 4099345475605, 20566288883610, 103150972979000, 517229100535265, 2592974460838005, 12996619961409245, 65131180719470549, 326348682636203655, 1634993474319839431 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Table of n, a(n) for n=0..27.

Emeric Deutsch, Emanuele Munarini, Simone Rinaldi, Skew Dyck paths, area, and superdiagonal bargraphs, Journal of Statistical Planning and Inference, Vol. 140, Issue 6, June 2010, pp. 1550-1562.

FORMULA

g.f.: (1-10*x+13*x^2-(1-7*x)*sqrt(1-6*x+5*x^2))/2/(5*x-1) .

D-finite with recurrence: n*(n+3)*a(n) +(-11*n^2-24*n+55)*a(n-1) +5*(7*n^2+9*n-71)*a(n-2) -25*(n-4) *(n+4)*a(n-3)=0.

MAPLE

g := (1-10*x+13*x^2-(1-7*x)*sqrt(1-6*x+5*x^2))/2/(5*x-1) ;

taylor(g, x=0, 40) ;

gfun[seriestolist](%) ;

CROSSREFS

Sequence in context: A095120 A304625 A151539 * A323919 A089164 A323290

Adjacent sequences:  A305552 A305553 A305554 * A305556 A305557 A305558

KEYWORD

nonn,easy

AUTHOR

R. J. Mathar, Jun 21 2018

STATUS

approved

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Last modified August 11 02:50 EDT 2020. Contains 336418 sequences. (Running on oeis4.)