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URL: https://oeis.org/A318700

⇱ A318700 - OEIS

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A318700
Positive numbers that contain odd and even digits.
4
10, 12, 14, 16, 18, 21, 23, 25, 27, 29, 30, 32, 34, 36, 38, 41, 43, 45, 47, 49, 50, 52, 54, 56, 58, 61, 63, 65, 67, 69, 70, 72, 74, 76, 78, 81, 83, 85, 87, 89, 90, 92, 94, 96, 98, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 112, 114, 116, 118, 120, 121, 122
OFFSET
1,1
COMMENTS
The sequence of first differences takes on the values {1, 2, 3} only, and each of these values occurs infinitely often (the values 1 and 2 are clear; for the value 3, note that consecutive numbers such as 199..9, 200..0 and 399..9, 400..0 that are excluded from the sequence occur infinitely often).
Numbers n such that A065031(n) is a term of A111066. - Felix Fröhlich, Sep 01 2018
Nonnegative integers excluding those such that digits in their decimal representation share all the same parity. - R. J. Cano, Sep 10 2018
EXAMPLE
49 and 50 are in the sequence but 19 and 20 are not.
MATHEMATICA
Select[Range@ 122, Union[Mod[IntegerDigits[#], 2]] == {0, 1} &] (* Michael De Vlieger, Sep 04 2018 *)
PROG
(PARI) is(n) = my(d=digits(n), v=[]); if(n < 10, return(0)); for(k=1, #d, v=concat(v, [d[k]%2])); vecmin(v)!=vecmax(v) \\ Felix Fröhlich, Sep 01 2018
(PARI) See Cano link.
CROSSREFS
KEYWORD
nonn,base,easy
AUTHOR
Enrique Navarrete, Aug 31 2018
STATUS
approved