A318700 Positive numbers that contain odd and even digits.

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

Links

Table of n, a(n) for n=1..63.

R. J. Cano, PARI program

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

Cf. A065031, A111066, A030141, A054684, A227870.

Sequence in context: A298298 A247393 A055983 * A180157 A309539 A273492

Adjacent sequences: A318697 A318698 A318699 * A318701 A318702 A318703

Keyword

nonn,base,easy

Author

Enrique Navarrete, Aug 31 2018

Status

approved