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Search: id:A113898
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| A113898 |
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Numbers n such that the value pi(n), the number of primes <= n, can be obtained deleting some of the repeating adjacent digits of n. |
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+0
1
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| 1196, 11373, 22517, 33597, 44639, 55646, 60062, 61159, 62256, 63346, 63347, 64448, 64544, 64555, 64577, 64588, 64599, 64611, 64655, 64668, 64700, 64711, 64722, 64774, 64884, 64992, 65545, 65770, 65880, 65881, 65990, 66644, 67746, 68841
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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Largest value below 10^7 is given by pi(110486)=10486.
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EXAMPLE
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pi(64668)=6468, pi(99551)=9551.
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MATHEMATICA
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lst = {}; p=0; While[p < 10^7, n=PrimePi[ ++p]; {sp, sn}=Split/@IntegerDigits@{p, n}; If[First/@sp==First/@sn && And@@GreaterEqual@@@Transpose[Length/@#&/@{sp, sn}], AppendTo[lst, p]]]; lst
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CROSSREFS
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Cf. A000720, A114924, A080794.
Sequence in context: A032530 A103172 A096955 this_sequence A059401 A059402 A137261
Adjacent sequences: A113895 A113896 A113897 this_sequence A113899 A113900 A113901
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KEYWORD
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base,nonn
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AUTHOR
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Giovanni Resta (g.resta(AT)iit.cnr.it), Jan 29 2006
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