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A113898 Numbers k such that the value pi(k), the number of primes <= k, can be obtained deleting some of the repeating adjacent digits of k. 0
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; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Largest value below 10^7 is given by pi(110486) = 10486.

LINKS

Table of n, a(n) for n=1..34.

EXAMPLE

pi(64668) = 6468, pi(99551) = 9551.

MATHEMATICA

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

CROSSREFS

Cf. A000720, A114924, A080794.

Sequence in context: A251915 A166221 A096955 * A059401 A059402 A252000

Adjacent sequences:  A113895 A113896 A113897 * A113899 A113900 A113901

KEYWORD

base,nonn

AUTHOR

Giovanni Resta, Jan 29 2006

STATUS

approved

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Last modified August 12 15:13 EDT 2022. Contains 356077 sequences. (Running on oeis4.)