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A059348
Third diagonal of array in A059347.
3
2, 2, 3, 4, 7, 10, 19, 28, 56, 84, 174, 264, 561, 858, 1859, 2860, 6292, 9724, 21658, 33592, 75582, 117572, 266798, 416024, 950912, 1485800, 3417340, 5348880, 12369285, 19389690, 45052515, 70715340, 165002460, 259289580, 607283490
OFFSET
2,1
COMMENTS
Same as A104722 except for leading term (both have rational g.f.s). - R. J. Mathar and Franklin T. Adams-Watters, May 19 2008
LINKS
F. R. Bernhart, Catalan, Motzkin and Riordan numbers, Discr. Math., 204 (1999), 73-112.
FORMULA
G.f.: 1 + ( (1 + x)*(1 - Sqrt[1 - 4*x^2])/(2*x^2))^2. - G. C. Greubel, Jan 08 2017
MATHEMATICA
CoefficientList[Series[1 + ( (1 + x)*(1 - Sqrt[1 - 4*x^2])/(2*x^2))^2, {x, 0, 50}], x] (* G. C. Greubel, Jan 08 2017 *)
PROG
(PARI) Vec( 1 + ( (1 + x)*(1 - sqrt(1 - 4*x^2))/(2*x^2))^2 + O(x^25)) \\ G. C. Greubel, Jan 08 2017
CROSSREFS
Sequence in context: A143590 A336030 A245620 * A110871 A243856 A173433
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Jan 27 2001
STATUS
approved