A262572 Concatenation of the numbers from 1 to n but omitting 2.

1, 13, 134, 1345, 13456, 134567, 1345678, 13456789, 1345678910, 134567891011, 13456789101112, 1345678910111213, 134567891011121314, 13456789101112131415, 1345678910111213141516, 134567891011121314151617, 13456789101112131415161718, 1345678910111213141516171819, 134567891011121314151617181920

Offset

1,2

Links

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

Mathematica

DeleteDuplicates[Table[FromDigits[Flatten[IntegerDigits[Complement[Range[n], {2}]]]], {n, 20}]] (* Robert Price, Nov 05 2018 *)

Crossrefs

For primes see A262298.

Cf. A007908, A262299, A262571-A262582.

See A262300 for more about this problem.

Sequence in context: A228277 A221153 A297335 * A132935 A132930 A130774

Adjacent sequences: A262569 A262570 A262571 * A262573 A262574 A262575

Keyword

nonn,base

Author

N. J. A. Sloane, Sep 25 2015

Status

approved