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A068827
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a(1) = 2; for n > 1, a(n) is the smallest prime > a(n-1) such that each successive digit in the concatenation of terms (that does not follow 9) is greater than the previous digit.
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1
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2, 3, 5, 7, 89, 127, 919, 1237, 8923, 8929, 8969, 12347, 89123, 89137, 89189, 89237, 89269, 89293, 89393, 89459, 89491, 89567, 89591, 89597, 89689, 89797, 89891, 89897, 91237, 91249, 123457, 891239, 891349, 891379, 891389, 891391
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OFFSET
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1,1
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LINKS
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EXAMPLE
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a(4) = 7 because 7 is the smallest prime such that, when it is concatenated to 235, we get 2357 and each successive digit is greater than the previous one.
a(5) = 89 because 89 is the smallest prime such that, when it is concatenated to 2357, we get 235789 and each successive digit is greater than the previous one.
a(6) = 127 because 127 is the smallest prime such that, when it is concatenated to 235789, we get 235789127 and each successive digit that does not follow 9 is greater than the previous one. (End)
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CROSSREFS
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KEYWORD
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nonn,base
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AUTHOR
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EXTENSIONS
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Edited by Larry Reeves (larryr(AT)acm.org), Jan 13 2003
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STATUS
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approved
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