OFFSET
1,1
MATHEMATICA
SequencePosition[Table[If[SequenceCount[IntegerDigits[n, 4], {1, 2}]>0 || SequenceCount[IntegerDigits[n, 4], {2, 1}]>0, 1, 0], {n, 500}], {1, 0}][[All, 1]] (* Harvey P. Dale, Aug 05 2021 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
STATUS
approved