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A106662 Smallest semiprime ending in exactly n 7's. 0
57, 77, 3777, 17777, 277777, 1777777, 17777777, 877777777, 3777777777, 17777777777, 577777777777, 1777777777777, 37777777777777, 877777777777777, 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(3)=3777 is a term because 3777 is the smallest semiprime ending in exactly three 7's.

CROSSREFS

Sequence in context: A043252 A044032 A104760 * A087922 A087921 A196580

Adjacent sequences:  A106659 A106660 A106661 * A106663 A106664 A106665

KEYWORD

base,nonn

AUTHOR

Shyam Sunder Gupta, May 12 2005

STATUS

approved

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Last modified June 26 21:14 EDT 2022. Contains 354885 sequences. (Running on oeis4.)