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A004343
Binomial coefficient C(5n,n-1).
6
1, 10, 105, 1140, 12650, 142506, 1623160, 18643560, 215553195, 2505433700, 29248649430, 342700125300, 4027810484880, 47465835030320, 560658857389200, 6635869816740560, 78682166288559225, 934433788613079150
OFFSET
1,2
REFERENCES
M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards Applied Math. Series 55, 1964 (and various reprintings), p. 828.
LINKS
M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards, Applied Math. Series 55, Tenth Printing, 1972 [alternative scanned copy].
FORMULA
From Peter Bala, Jul 21 2024: (Start)
a(n) = Sum_{k = 0..n-1} binomial(4*n+k, k).
a(n) = 5*(5*n - 1)*(5*n - 2)*(5*n - 3)*(5*n - 4)/((4*n - 4)*(4*n - 2)*(4*n - 1)*(4*n + 1)) * a(n-1) with a(1) = 1. (End)
CROSSREFS
KEYWORD
nonn,easy
STATUS
approved