OFFSET
1,2
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
S. Giraudo, Combinatorial operads from monoids, arXiv preprint arXiv:1306.6938 [math.CO], 2013-2015. See Sect. 3.1.3.
MAPLE
R[1]:= [1]:
for d from 2 to 6 do
R[d]:= map(t -> seq(10*t+j, j=1..min((t mod 10)+1, 9)), R[d-1])
od:
A:= map(op, [seq(R[d], d=1..6)]); # Robert Israel, Jan 31 2017
MATHEMATICA
desQ[n_]:=Module[{idn=IntegerDigits[n]}, idn[[1]]==1&&FreeQ[idn, 0]&&Max[ Differences[ idn]]<2]; Select[Range[13000], desQ] (* Harvey P. Dale, Feb 19 2017 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Antti Karttunen, May 14 2002
STATUS
approved