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Search: id:A125220
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| A125220 |
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Numbers n such that binomial(3n, n) - 1 is prime. |
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+0
8
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| 1, 3, 7, 11, 49, 88, 93, 196, 216, 519, 655, 722, 858, 905, 991, 1654, 2277, 3275, 4214
(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. A125221 = 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: A141161 A141162 A005372 this_sequence A016081 A105762 A057469
Adjacent sequences: A125217 A125218 A125219 this_sequence A125221 A125222 A125223
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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 25 2006
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EXTENSIONS
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a(16) - a(19) from Robert G. Wilson v (rgwv(AT)rgwv.com), Nov 26 2006
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