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A071070 Minimal set of composite-strings in base 10. 11
4, 6, 8, 9, 10, 12, 15, 20, 21, 22, 25, 27, 30, 32, 33, 35, 50, 51, 52, 55, 57, 70, 72, 75, 77, 111, 117, 171, 371, 711, 713, 731 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Any composite number contains in its digits at least one of the term of this sequence and there is no smaller set.

REFERENCES

J. Shallit, Minimal primes, in J.Recreational Mathematics, vol. 30.2, pp. 113-117,1999-2000

J.-P. Delahaye, "Pour la science", (French edition of Scientific American), Juin 2002, p. 99

LINKS

Table of n, a(n) for n=1..32.

J. Shallit, Minimal primes, J. Recreational Mathematics, vol. 30.2, pp. 113-117, 1999-2000.

CROSSREFS

Cf. A071062, A071071, A071072, A071073.

Sequence in context: A248010 A067013 A141607 * A047820 A248807 A034878

Adjacent sequences:  A071067 A071068 A071069 * A071071 A071072 A071073

KEYWORD

fini,full,nice,nonn,base

AUTHOR

Benoit Cloitre, May 26 2002

STATUS

approved

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Last modified November 21 11:17 EST 2014. Contains 249777 sequences.