OFFSET
1,1
MATHEMATICA
Select[Range@400, (s=#; Differences[Count[IntegerDigits[s], #]&/@{0, 9}]=={1})&] (* Giorgos Kalogeropoulos, Jul 04 2021 *)
Select[Range[400], DigitCount[#, 10, 0]+1==DigitCount[#, 10, 9]&] (* Harvey P. Dale, Feb 06 2023 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
STATUS
approved