A033070 Numbers with the property that all pairs of consecutive base-5 digits differ by 1.

1, 2, 3, 4, 5, 7, 11, 13, 17, 19, 23, 26, 36, 38, 55, 57, 67, 69, 86, 88, 98, 117, 119, 130, 132, 180, 182, 192, 194, 276, 286, 288, 336, 338, 348, 430, 432, 442, 444, 492, 494, 586, 588, 598, 651, 661, 663, 901, 911, 913, 961, 963

Offset

1,2

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Maple

extend:= proc(x) local t;
  t:= x mod 5;
  if t = 0 then 5*x+1
  elif t = 4 then 5*x+3
  else 5*x+t-1, 5*x+t+1
  fi
end proc;
extend := proc (x) local t; t := `mod`(x, 5); if t = 0 then
   5*x+1 elif t = 4 then 5*x+3 else 5*x+t-1, 5*x+t+1 end if end
   proc
L:= [1, 2, 3, 4]: R:= op(L):
while nops([R])<100 do
  L:= map(extend, L);
  R:= R, op(L);
od:
R; # Robert Israel, Dec 21 2025

Mathematica

Join[Range[4], Select[Range[1000], Union[Abs[Differences[IntegerDigits[ #, 5]]]]=={1}&]] (* Harvey P. Dale, Dec 28 2011 *)

Crossrefs

Sequence in context: A285304 A036844 A284696 * A211781 A348283 A046022

Adjacent sequences: A033067 A033068 A033069 * A033071 A033072 A033073

Keyword

nonn,base

Author

Clark Kimberling

Status

approved