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 A262576 Concatenation of the numbers from 1 to n but omitting 6. 0
 1, 12, 123, 1234, 12345, 123457, 1234578, 12345789, 1234578910, 123457891011, 12345789101112, 1234578910111213, 123457891011121314, 12345789101112131415, 1234578910111213141516, 123457891011121314151617, 12345789101112131415161718, 1234578910111213141516171819, 123457891011121314151617181920 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS The only prime among the first 98 terms is a(6) = 123457. Does the sequence contain any other primes? No additional primes through the first 2000 terms. - Harvey P. Dale, Sep 27 2018 Differs from A132943 at about the 28th terms. No primes, other than a(6), through a(10000). - Robert Price, Nov 03 2018 LINKS MATHEMATICA Module[{nn=20, c}, c=Drop[Range[nn], {6}]; Table[FromDigits[Flatten[ IntegerDigits/@ Take[c, n]]], {n, nn-1}]] (* Harvey P. Dale, Sep 27 2018 *) CROSSREFS Cf. A132943. Cf. A007908, A262299, A262571-A262582. See A262300 for more about this problem. Sequence in context: A262578 A262577 A132943 * A262575 A187871 A187869 Adjacent sequences:  A262573 A262574 A262575 * A262577 A262578 A262579 KEYWORD nonn,base AUTHOR N. J. A. Sloane, Sep 25 2015 STATUS approved

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Last modified April 16 17:01 EDT 2021. Contains 343050 sequences. (Running on oeis4.)