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

1,2

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.

Links

Table of n, a(n) for n=1..19.

Mathematica

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

Crossrefs

Cf. A007908, A262299, A262571-A262582.

See A262300 for more about this problem.

Sequence in context: A007908 A262582 A262581 * A262579 A057932 A262578

Adjacent sequences: A262577 A262578 A262579 * A262581 A262582 A262583

Keyword

nonn,base

Author

N. J. A. Sloane, Sep 25 2015

Status

approved