OFFSET
1,2
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
MAPLE
for i from 0 to 9 do S[1, i]:= {i} od:
for d from 2 to 4 do
for i from 0 to 9 do
S[d, i]:= `union`(seq(map(t -> i*10^(d-1)+t, S[d-1, j]), j={$0..9} minus {$(i-3)..(i+3)}))
od od:
seq(seq(op(sort(convert(S[d, i], list))), i=1..9), d=1..4); # Robert Israel, Sep 28 2025
MATHEMATICA
Select[Range[200], Min[Abs[Differences[IntegerDigits[#]]]]>3&] (* Harvey P. Dale, Dec 15 2014 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
STATUS
approved
