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A262575 Concatenation of the numbers from 1 to n but omitting 5. 2

%I

%S 1,12,123,1234,12346,123467,1234678,12346789,1234678910,123467891011,

%T 12346789101112,1234678910111213,123467891011121314,

%U 12346789101112131415,1234678910111213141516,123467891011121314151617,12346789101112131415161718,1234678910111213141516171819,123467891011121314151617181920

%N Concatenation of the numbers from 1 to n but omitting 5.

%C The only primes among the first 98 terms are 123467891011 and 123467891011121314151617. See A262552 for further primes in this sequence.

%t DeleteDuplicates[Table[FromDigits[Flatten[IntegerDigits[Complement[Range[n], {5}]]]], {n, 20}]] (* _Robert Price_, Nov 05 2018 *)

%Y Cf. A007908, A262299, A262571-A262582.

%Y See A262300 for more about this problem.

%Y For primes see A262552.

%K nonn,base

%O 1,2

%A _N. J. A. Sloane_, Sep 25 2015

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Last modified May 12 13:46 EDT 2021. Contains 343823 sequences. (Running on oeis4.)