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A002503
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Numbers n such that binomial(2n,n) is divisible by (n+1)^2.
(Formerly M3840)
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6
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5, 14, 27, 41, 44, 65, 76, 90, 109, 125, 139, 152, 155, 169, 186, 189, 203, 208, 209, 219, 227, 230, 237, 265, 275, 298, 307, 311, 314, 321, 324, 329, 344, 377, 413, 419, 428, 434, 439, 441, 449, 458, 459, 467, 475
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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REFERENCES
| H. Balakran, On the values of n which make (2n)!/(n+1)!(n+1)! an integer, J. Indian Math. Soc., Vol. 18, 1929, 97-100.
P. Erdos, R. L. Graham, I. Z. Ruzsa and E. G. Straus, On the prime factors of C(2n,n), Math. Comp. 29 (1975), 83-92.
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
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LINKS
| T. D. Noe, Table of n, a(n) for n=1..1000
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CROSSREFS
| Positions of zeros in A065350.
Cf. A000108, A065344-A065349.
A067348(n+2)/2 - 1.
Sequence in context: A071421 A185233 A065351 * A014106 A110325 A140342
Adjacent sequences: A002500 A002501 A002502 * A002504 A002505 A002506
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KEYWORD
| nonn,easy,nice
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AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com), Mira Bernstein (mira(AT)math.berkeley.edu)
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EXTENSIONS
| Balakran reference corrected by T. D. Noe, Jan 16 2007
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