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A004936 Numerator of (binomial(2*n-2,n-1)/n!)^2. 1
1, 1, 1, 25, 49, 49, 121, 20449, 20449, 5909761, 17631601, 17631601, 55190041, 55190041, 55190041, 46414824481, 154341336769, 154341336769, 427538329, 585299972401, 585299972401, 983889253606081, 3438962627443561 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,4

REFERENCES

Valtr, Pavel; The probability that n random points in a triangle are in convex position. Combinatorica 16 (1996), no. 4, 567-573.

LINKS

Table of n, a(n) for n=1..23.

Eric Weisstein's World of Mathematics, Sylvester's Four-Point Problem.

MATHEMATICA

Numerator[Table[(Binomial[2n-2, n-1]/n!)^2, {n, 30}]] (* Harvey P. Dale, May 30 2012 *)

CROSSREFS

Sequence in context: A106632 A284666 A090093 * A062058 A273510 A198591

Adjacent sequences:  A004933 A004934 A004935 * A004937 A004938 A004939

KEYWORD

nonn

AUTHOR

N. J. A. Sloane.

STATUS

approved

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Last modified July 28 18:53 EDT 2021. Contains 346335 sequences. (Running on oeis4.)