

A165449


Write the prime numbers in a string: 2357111317192329... (cf. A033308). The sequence gives the first position in the string for natural numbers.


3



5, 1, 2, 21, 3, 31, 4, 41, 12, 47, 5, 62, 7, 22, 77, 32, 9, 95, 11, 589, 110, 113, 1, 128, 131, 137, 63, 149, 15, 158, 8, 14, 123, 24, 2, 188, 19, 42, 72, 206, 21, 215, 23, 227, 233, 236, 25, 248, 75, 257, 78, 263, 27, 269, 275, 278, 3, 290, 29, 299, 31, 829
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OFFSET

1,1


COMMENTS

Same as A229190 but omitting the a(0) term.
Defined for all a by the normality of the CopelandErdős constant.  Aaron Weiner, Sep 19 2013


LINKS

Nathaniel Johnston, Table of n, a(n) for n = 1..5000


EXAMPLE

The first occurence of "111" in the string is 5, so a(111)=5.


MAPLE

with(StringTools): s:="": for n from 1 to 300 do s:=cat(s, convert(ithprime(n), string)): od: seq(Search(convert(n, string), s), n=1..62); # Nathaniel Johnston, May 26 2011


CROSSREFS

Cf. A229190 (same sequence but including the a(0) term).
Cf. A031297.
Sequence in context: A085608 A258339 A197080 * A019114 A201526 A091384
Adjacent sequences: A165446 A165447 A165448 * A165450 A165451 A165452


KEYWORD

easy,base,nonn


AUTHOR

Rémy Sigrist, Sep 20 2009


STATUS

approved



