A122975 - OEIS

A122975

Numbers containing no successive even ternary digits.

1, 2, 3, 4, 5, 7, 10, 12, 13, 14, 16, 21, 22, 23, 30, 31, 32, 37, 39, 40, 41, 43, 48, 49, 50, 64, 66, 67, 68, 70, 91, 93, 94, 95, 97, 111, 112, 113, 118, 120, 121, 122, 124, 129, 130, 131, 145, 147, 148, 149, 151, 192, 193, 194, 199, 201, 202, 203, 205, 210, 211, 212

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

LINKS

Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

Index entries for 3-automatic sequences.

MATHEMATICA

nsetdQ[n_]:=With[{idn3=If[EvenQ[#], 1, 0]&/@IntegerDigits[n, 3]}, SequenceCount[ idn3, {1, 1}]==0]; Select[Range[300], nsetdQ] (* Harvey P. Dale, Oct 10 2022 *)

PROG

(PARI) is(n)=while(n>5, if(bitand(1<<(n%9), 325), return(0)); n\=3); 1 \\ Charles R Greathouse IV, Feb 15 2017

CROSSREFS

Subsequence of A032974.

Cf. A007089.

Sequence in context: A048183 A255641 A365093 * A089597 A022957 A036028

Adjacent sequences: A122972 A122973 A122974 * A122976 A122977 A122978

KEYWORD

nonn,base,easy

AUTHOR

Reinhard Zumkeller, Sep 21 2006

EXTENSIONS

Named edited by Charles R Greathouse IV, Feb 15 2017

STATUS

approved