A106662 Smallest semiprime ending in exactly n 7's.

57, 77, 3777, 17777, 277777, 1777777, 17777777, 877777777, 3777777777, 17777777777, 577777777777, 1777777777777, 37777777777777, 877777777777777, 4777777777777777, 37777777777777777, 277777777777777777

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