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A302093 a(n) = floor(C(n/2)*C(n/2+1)), where C = Catalan numbers (A000108). 0
1, 1, 2, 4, 10, 25, 70, 199, 588, 1784, 5544, 17569, 56628, 185202, 613470, 2054998, 6952660, 23732911, 81662152, 283026021, 987369656, 3465222945, 12228193432, 43369190282, 154532114800, 552998717472, 1986841476000, 7164993393905, 25928281261800, 94132464529902 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Table of n, a(n) for n=0..29.

EXAMPLE

k         a(k) is prime

2          2

7          199

11         17569

17         23732911

81         102313363987695596246576033222404783284068513

619        200823128294216578246...307006792344011246479 (366 digits)

MATHEMATICA

Table[Floor[CatalanNumber[n/2] CatalanNumber[n/2 + 1]], {n, 0, 35}]

CROSSREFS

Cf. A000108, A005568 (bisection, even part), A005817.

Sequence in context: A052829 A001998 A005817 * A292617 A148093 A206289

Adjacent sequences:  A302090 A302091 A302092 * A302094 A302095 A302096

KEYWORD

nonn

AUTHOR

Vincenzo Librandi, Apr 11 2018

STATUS

approved

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Last modified February 18 21:20 EST 2020. Contains 332028 sequences. (Running on oeis4.)