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A262574 Concatenation of the numbers from 1 to n but omitting 4. 0

%I

%S 1,12,123,1235,12356,123567,1235678,12356789,1235678910,123567891011,

%T 12356789101112,1235678910111213,123567891011121314,

%U 12356789101112131415,1235678910111213141516,123567891011121314151617,12356789101112131415161718,1235678910111213141516171819,123567891011121314151617181920

%N Concatenation of the numbers from 1 to n but omitting 4.

%C The only prime among the first 98 terms is a(8) = 12356789. Does the sequence contain any other primes?

%C No other primes through a(10000). - _Robert Price_, Nov 03 2018

%t DeleteDuplicates[Table[FromDigits[Flatten[IntegerDigits[Complement[Range[n], {4}]]]], {n, 20}]] (* _Robert Price_, Nov 05 2018 *)

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

%Y See A262300 for more about this problem.

%K nonn,base

%O 1,2

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

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Last modified May 7 01:15 EDT 2021. Contains 343635 sequences. (Running on oeis4.)