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Search: id:A114757
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| A114757 |
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Smallest prime of the form: n successive positive integers in ascending order followed by a 9. a(3k) = 0 as no such prime exists. |
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+0
8
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| 19, 239, 0, 23459, 345679, 0, 23456789, 234567899, 0, 2345678910119, 6789101112131415169, 0, 313233343536373839404142439, 36373839404142434445464748499, 0, 123456789101112131415169
(list; graph; listen)
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OFFSET
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1,1
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EXAMPLE
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a(4) = 23459, four successive positive integers 2,3,4,5 in ascending order followed by a 9.
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MATHEMATICA
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a[n_]:=If[Mod[n, 3]==0, 0, (For[m=1, (v={}; Do[v=Join[v, IntegerDigits[k]], {k, m, m+n-1}]); !PrimeQ[10FromDigits[v]+9], m++ ]; 10FromDigits[v]+9)]; Table[a[n], {n, 17}] - Farideh Firoozbakht
f[n_] := Block[{t = Range@n}, If[ Mod[n, 3] == 0, 0, While[p = FromDigits@Flatten@IntegerDigits@Join[t, {9}]; !PrimeQ@p, t++ ]; p]]; Array[f, 16] (* Robert G. Wilson v *)
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CROSSREFS
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Cf. A114754, A114755, A114756, A114758, A114759, A112716, A108145.
Sequence in context: A025960 A022033 A025938 this_sequence A142615 A021814 A025933
Adjacent sequences: A114754 A114755 A114756 this_sequence A114758 A114759 A114760
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KEYWORD
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base,nonn
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AUTHOR
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Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Jan 01 2006
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EXTENSIONS
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Extended by Robert G. Wilson v (rgwv(at)rgwv.com), Ray Chandler (rayjchandler(AT)sbcglobal.net) and Farideh Firoozbakht (f.firoozbakht(AT)math.ui.ac.ir), Jan 02 2006
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