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Search: id:A067365
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| A067365 |
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a(n)=p-n!^5, where p is the smallest prime > n!^5+1. |
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+0
4
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| 2, 5, 13, 13, 7, 7, 11, 71, 23, 19, 197, 17, 101, 53, 17, 47, 73, 97, 53, 433, 251, 251, 47, 263, 281, 353, 53, 61, 179, 41, 53, 401, 449, 79, 89, 1283, 367, 2011, 139, 227, 1597, 1657, 1123, 397, 131, 727, 137, 167, 89, 379, 421, 653, 223, 373, 2221, 1447
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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The first 60 terms are primes. Are all terms prime? For n!^i, with 0<i<6, it looks like the terms are prime, too (see references). But for n!^6: a(28)=1189=29*41.
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LINKS
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Cyril Banderier, Fortunate Numbers
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MATHEMATICA
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a[n_] := For[i=2, True, i++, If[PrimeQ[n!^5+i], Return[i]]]
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PROGRAM
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(MuPAD) for n from 1 to 50 do f := n!^5:a := nextprime(f+2)-f:print(a) end_for
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CROSSREFS
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Cf. A037153, A037153, A005235, A067362, A067363, A067364.
Adjacent sequences: A067362 A067363 A067364 this_sequence A067366 A067367 A067368
Sequence in context: A135329 A114508 A139023 this_sequence A112838 A111296 A089728
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KEYWORD
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nonn
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AUTHOR
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Frank Buss (fb(AT)frank-buss.de), Jan 19 2002
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EXTENSIONS
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Edited by Dean Hickerson (dean(AT)math.ucdavis.edu), Mar 02 2002
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