A204341 Smith numbers with either no internal digits or all internal digits are 0.

4, 22, 27, 58, 85, 94, 202, 706, 8005, 80005, 700006, 800005, 7000000000000006, 80000000000000000005, 80000000000000000000005, 70000000000000000000000000006, 80000000000000000000000000000000000005, 700000000000000000000000000000000000000000000006

Offset: 1

Author

Arkadiusz Wesolowski, Jan 14 2012

Keywords

• base
• nonn

Comments

All semiprimes of the form 7*10^n + 6 and 8*10^n + 5 are in the sequence.

Links

• Vincenzo Librandi, Table of n, a(n) for n = 1..34
• Eric Weisstein's World of Mathematics, Smith Number

Crossrefs

Cf. A006753.

Programs

Mathematica

e = 47; Sort[Join[{27}, 2*Select[Flatten[Union[Table[(2*10^n + 2)/2, {n, 0, e}], Table[(a*10^n + 13 - a)/2, {a, {5, 7, 9}}, {n, e}]]], PrimeQ], 5*Select[Table[(8*10^n + 5)/5, {n, e}], PrimeQ]]]