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A104760 Smallest semiprime containing exactly n 7's. 2
57, 77, 3777, 17777, 277777, 1777777, 17777777, 707777777, 3777777777, 17777777777, 577777777777, 1777777777777, 37777777777777, 757777777777777, 4777777777777777, 37777777777777777, 277777777777777777 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..17.

EXAMPLE

a(2)=77 because 77 is the smallest semiprime containing exactly two 7's.

CROSSREFS

Sequence in context: A039429 A043252 A044032 * A106662 A087922 A087921

Adjacent sequences:  A104757 A104758 A104759 * A104761 A104762 A104763

KEYWORD

base,nonn

AUTHOR

Shyam Sunder Gupta, Apr 24 2005

STATUS

approved

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Last modified September 19 15:24 EDT 2019. Contains 327198 sequences. (Running on oeis4.)