A044794 - OEIS

%I #7 Nov 14 2020 18:21:15

%S 81,181,281,381,481,581,681,781,819,881,981,1081,1181,1281,1381,1481,

%T 1581,1681,1781,1819,1881,1981,2081,2181,2281,2381,2481,2581,2681,

%U 2781,2819,2881,2981,3081,3181,3281,3381,3481,3581

%N Numbers n such that string 8,1 occurs in the base 10 representation of n but not of n+1.

%t SequencePosition[Table[If[SequenceCount[IntegerDigits[n],{8,1}]>0,1,0],{n,4000}],{1,0}][[All,1]] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Nov 14 2020 *)

%K nonn,base

%O 1,1

%A _Clark Kimberling_