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Search: id:A105019
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| A105019 |
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Smallest prime of just n consecutive primes all of which are irregular. |
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+0
2
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| 37, 101, 461, 283, 607, 2357, 13693, 15733, 149969, 22283, 8597, 2580511, 2111491, 670619
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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The author hereby expresses his gratitude to T.D. Noe (noe(AT)sspectra.com) for supplying him with a list of the first irregular primes to 12 million. - Robert G. Wilson v (rgwv(AT)rgwv.com), Mar 31 2005
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EXAMPLE
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a(1)=37 because neither 31 nor 41, its neighboring primes, are irregular.
a(2)=101 because neither 97 nor 107 are irregular, they being the neighbors of 101&103 which are irregular.
a(3)=461 because neither 457 nor 479 are irregular, they being the neighbors of {461, 463, 467} which are all irregular
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MATHEMATICA
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fQ[n_] := Block[{ p = Prime[ n ], k = 1}, While[ 2k <= p - 3 && Mod[ Numerator[ BernoulliB[ 2k]], p] != 0, k++ ]; If[ 2k != p - 1, True, False]]; Select[ Range[2, 250], fQ[ # ] &]; s = {}; Do[ If[ fQ[n], AppendTo[s, n]; Print[{n, Prime[n]}]], {n, 1500}]
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CROSSREFS
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Cf. A000928, A105018.
Sequence in context: A044605 A130229 A142941 this_sequence A090496 A005107 A139934
Adjacent sequences: A105016 A105017 A105018 this_sequence A105020 A105021 A105022
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KEYWORD
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nonn
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AUTHOR
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Robert G. Wilson v (rgwv(AT)rgwv.com), Mar 31 2005
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EXTENSIONS
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More terms from Robert G. Wilson v (rgwv(AT)rgwv.com), Mar 31 2005
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