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Search: id:A125221
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| A125221 |
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Numbers n such that binomial(3n, n) + 1 is prime. |
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+0
9
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| 0, 12, 43, 53, 120, 121, 184, 778, 823, 1179, 1212, 1670, 3187, 3353, 4282, 5420, 5592, 5826, 6526, 7405, 7581, 7619, 13213
(list; graph; listen)
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OFFSET
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1,2
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MATHEMATICA
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Do[f=Binomial[3n, n]+1; If[PrimeQ[f], Print[n]], {n, 1, 1000}]
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CROSSREFS
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Cf. A125220 = numbers n such that binomial(3n, n) - 1 is prime. Cf. A066699 = numbers n such that binomial(2n, n) + 1 is prime. Cf. A066726 = numbers n such that binomial(2n, n) - 1 is prime.
Sequence in context: A122973 A074356 A088826 this_sequence A082829 A003357 A004466
Adjacent sequences: A125218 A125219 A125220 this_sequence A125222 A125223 A125224
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KEYWORD
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hard,more,nonn
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AUTHOR
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Alexander Adamchuk (alex(AT)kolmogorov.com), Nov 24 2006
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EXTENSIONS
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a(10) - a(15) from Robert G. Wilson v (rgwv(AT)rgwv.com), Nov 26 2006
More terms from Stefan Steinerberger (stefan.steinerberger(AT)gmail.com), Sep 07 2007
5 more terms from Ryan Propper (rpropper(AT)cs.stanford.edu), Jan 01 2008
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