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Search: id:A157048
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| A157048 |
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a(n) = the smallest integer > p(n) that is coprime to (p(n+1)-p(n)), where p(n) is the nth prime. |
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2
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| 3, 5, 7, 9, 13, 15, 19, 21, 25, 31, 35, 39, 43, 45, 49, 55, 61, 65, 69, 73, 77, 81, 85, 91, 99, 103, 105, 109, 111, 115, 129, 133, 139, 141, 151, 155, 161, 165, 169, 175, 181, 183, 193, 195, 199, 203, 215, 225, 229, 231, 235, 241, 243, 253, 259, 265, 271, 275, 279
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OFFSET
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1,1
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EXAMPLE
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The 11th prime is 31. The 12th prime is 37. 37-31 = 6. The smallest integer > 31 that is coprime to 6 is 35, which is a(11).
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MATHEMATICA
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f[n_] := Block[{k, p = Prime@n, q = Prime[n + 1]}, k = p + 1; While[ GCD[q - p, k] > 1, k++ ]; k]; Array[f, 59] [From Robert G. Wilson v (rgwv(AT)rgwv.com), Apr 08 2009]
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CROSSREFS
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A157049, A001223
Sequence in context: A003553 A003532 A156982 this_sequence A003543 A114513 A003524
Adjacent sequences: A157045 A157046 A157047 this_sequence A157049 A157050 A157051
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KEYWORD
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hard,nonn
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AUTHOR
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Leroy Quet (q1qq2qqq3qqqq(AT)yahoo.com), Feb 22 2009
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EXTENSIONS
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More terms from Robert G. Wilson v (rgwv(AT)rgwv.com), Apr 08 2009
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