A262580 Concatenation of the numbers from 1 to n but omitting 10.

1, 12, 123, 1234, 12345, 123456, 1234567, 12345678, 123456789, 12345678911, 1234567891112, 123456789111213, 12345678911121314, 1234567891112131415, 123456789111213141516, 12345678911121314151617, 1234567891112131415161718, 123456789111213141516171819, 12345678911121314151617181920

Offset: 1

Author

N. J. A. Sloane, Sep 25 2015

Keywords

• nonn
• base

Comments

The smallest prime in this sequence is the 61457-digit (probable) prime a(14512) = 123456789111213...14513 found by David Broadhurst on Sep 28 2015.

Crossrefs

Cf. A007908, A262299, A262571-A262582.

See A262300 for more about this problem.

Programs

Mathematica

DeleteDuplicates[Table[FromDigits[Flatten[IntegerDigits[Complement[Range[n], {10}]]]], {n, 20}]] (* Robert Price, Nov 05 2018 *)