

A076730


Maximum number of (distinct) primes that an ndigit number may shelter (i.e., primes contained among all digital substrings' permutations).


3



1, 4, 11, 31, 106, 402, 1953, 10542, 75447, 398100, 3605464
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OFFSET

1,2


COMMENTS

See sequence A134596 for the (least, n digit) numbers m which yield these maximum values for A039993.  M. F. Hasler, Mar 11 2014


LINKS

Table of n, a(n) for n=1..11.
M. Keith, Integers containing many embedded primes
W. Schneider, MATHEWS, Primeval Numbers


FORMULA

a(n) = max { A039993(m); m in A072857 and m < 10^n }.  M. F. Hasler, Mar 12 2014


EXAMPLE

We have a(3)=11, since among numbers 100 through 999, the smallest ones having 5, 6, 7, 8, 10, 11 embedded primes are respectively 107, 127, 113, 167, 179, 137 (the last of these being the first reaching the maximum number of 11 embedded primes, viz. 3, 7, 13, 17, 31, 37, 71, 73, 137, 173, 317).


PROG

(PARI) a(n, m=0)=for(k=10^(n1), 10^n1, A039993(k)>m&&m=A039993(k)); m \\ M. F. Hasler, Mar 09 2014


CROSSREFS

Cf. A072857, A076449.
Cf. A075053 (a variant of A039993), A134597 (variant or incorrect version of A134596).
Sequence in context: A077995 A276293 A176573 * A084757 A155962 A027153
Adjacent sequences: A076727 A076728 A076729 * A076731 A076732 A076733


KEYWORD

hard,more,base,nonn


AUTHOR

Lekraj Beedassy, Nov 08 2002


EXTENSIONS

Link fixed by Charles R Greathouse IV, Aug 13 2009
a(6) from M. F. Hasler, Mar 09 2014
a(7)  a(11) from Robert G. Wilson v, Mar 11 2014


STATUS

approved



