A318275 Numbers with digits in nondecreasing order and with multiplicative digital root > 0.

1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 12, 13, 14, 15, 16, 17, 18, 19, 22, 23, 24, 26, 27, 28, 29, 33, 34, 35, 36, 37, 38, 39, 44, 46, 47, 48, 49, 57, 66, 67, 68, 77, 79, 88, 89, 99, 111, 112, 113, 114, 115, 116, 117, 118, 119, 122, 123, 124, 126, 127, 128, 129, 133, 134

Offset

1,2

Comments

This sequence is a primitive sequence of A277061, it has digits in nondecreasing order. Terms in A277061 can be found by permuting digits of terms of this sequence.

Links

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

Maple

dr:= proc(n) option remember; local v;
     v:= n;
     while v >= 10 do v:= convert(convert(v, base, 10), `*`) od;
     v
end proc:
S:= [$1..9]: R:= op(S):
for d from 2 to 3 do
  S:= map(proc(t) local i; seq(10*t+i, i=(t mod 10) .. 9) end proc, S);
  V:= select(t -> dr(t) > 0, S); count:= count + nops(V);
  R:= R, op(V);
od:
R; # Robert Israel, Jun 09 2026

Mathematica

Select[Range@ 134, And[FixedPoint[Times @@ IntegerDigits@ # &, #] != 0, AllTrue[Differences@ IntegerDigits@ #, # >= 0 &]] &] (* Michael De Vlieger, Aug 25 2018 *)

Crossrefs

Intersection of A009994 and A277061.

Cf. A299690.

Sequence in context: A239215 A055571 A132781 * A173646 A274125 A070698

Adjacent sequences: A318272 A318273 A318274 * A318276 A318277 A318278

Keyword

nonn,base,changed

Author

David A. Corneth, Aug 23 2018

Status

approved