login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A044649
Numbers n such that string 1,8 occurs in the base 9 representation of n but not of n+1.
1
17, 98, 161, 179, 260, 341, 422, 503, 584, 665, 746, 827, 890, 908, 989, 1070, 1151, 1232, 1313, 1457, 1475, 1556, 1619, 1637, 1718, 1799, 1880, 1961, 2042, 2123, 2204, 2285, 2348, 2366, 2447, 2528, 2609, 2690, 2771, 2852
OFFSET
1,1
LINKS
MATHEMATICA
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 *)
SequencePosition[Table[If[SequenceCount[IntegerDigits[n, 9], {1, 8}]>0, 1, 0], {n, 3000}], {1, 0}][[;; , 1]] (* Harvey P. Dale, Jan 30 2024 *)
CROSSREFS
Sequence in context: A282997 A231667 A044268 * A253707 A160827 A231671
KEYWORD
nonn,base
STATUS
approved