|
|
A043254
|
|
Numbers k such that 5 and 9 occur juxtaposed in the base-10 representation of k but not of k-1.
|
|
1
|
|
|
59, 95, 159, 195, 259, 295, 359, 395, 459, 495, 559, 590, 659, 695, 759, 795, 859, 895, 950, 995, 1059, 1095, 1159, 1195, 1259, 1295, 1359, 1395, 1459, 1495, 1559, 1590, 1659, 1695, 1759, 1795, 1859, 1895, 1950, 1995, 2059
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
LINKS
|
|
|
MAPLE
|
N:= 10000: # to get all terms <= N
V:= Vector(N, n -> StringTools:-RegMatch("59|95", convert(n, string))):
select(t -> V[t] and not V[t-1], [$2..N]); # Robert Israel, Dec 11 2015
|
|
MATHEMATICA
|
SequencePosition[Table[If[SequenceCount[IntegerDigits[n], {5, 9}]>0 || SequenceCount[ IntegerDigits[n], {9, 5}]>0, 1, 0], {n, 2500}], {0, 1}][[All, 2]] (* Harvey P. Dale, Jul 20 2022 *)
|
|
CROSSREFS
|
Cf. A044034 (similar but with k+1 instead).
|
|
KEYWORD
|
nonn,base
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|