A044649 - OEIS

A044649

Numbers n such that string 1,8 occurs in the base 9 representation of n but not of n+1.

%I #12 Jan 30 2024 13:15:31

%S 17,98,161,179,260,341,422,503,584,665,746,827,890,908,989,1070,1151,

%T 1232,1313,1457,1475,1556,1619,1637,1718,1799,1880,1961,2042,2123,

%U 2204,2285,2348,2366,2447,2528,2609,2690,2771,2852

%N Numbers n such that string 1,8 occurs in the base 9 representation of n but not of n+1.

%H Harvey P. Dale, <a href="/A044649/b044649.txt">Table of n, a(n) for n = 1..1000</a>

%t Flatten[Position[Partition[Table[If[MemberQ[Partition[ IntegerDigits[ n,9],2,1],{1,8}],1,0],{n,3000}],2,1],{1,0}]] (* _Harvey P. Dale_, Mar 13 2015 *)

%t SequencePosition[Table[If[SequenceCount[IntegerDigits[n,9],{1,8}]>0,1,0],{n,3000}],{1,0}][[;;,1]] (* _Harvey P. Dale_, Jan 30 2024 *)

%K nonn,base

%O 1,1

%A _Clark Kimberling_