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A033176 Threes and ones. 0
31, 31331, 313313331, 31331333133331, 31331333133331333331, 313313331333313333313333331, 31331333133331333331333333133333331, 31331333133331333331333333133333331333333331 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

This sequence contains many primes.

REFERENCES

F. Smarandache, Properties of numbers, University of Craiova, 1973

LINKS

Table of n, a(n) for n=1..8.

FORMULA

a(n) has increasing groups of 31, 331, ..., 33...31 (n times 3) concatenated.

CROSSREFS

Sequence in context: A263585 A176349 A262716 * A263163 A188956 A218142

Adjacent sequences:  A033173 A033174 A033175 * A033177 A033178 A033179

KEYWORD

nonn,easy,base,less

AUTHOR

Jan Jensen (dorul(AT)post6.tele.dk)

EXTENSIONS

More terms from Erich Friedman.

STATUS

approved

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Last modified July 4 16:24 EDT 2020. Contains 335448 sequences. (Running on oeis4.)