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%I #16 Jul 20 2022 16:30:08
%S 59,95,159,195,259,295,359,395,459,495,559,590,659,695,759,795,859,
%T 895,950,995,1059,1095,1159,1195,1259,1295,1359,1395,1459,1495,1559,
%U 1590,1659,1695,1759,1795,1859,1895,1950,1995,2059
%N Numbers k such that 5 and 9 occur juxtaposed in the base-10 representation of k but not of k-1.
%H Robert Israel, <a href="/A043254/b043254.txt">Table of n, a(n) for n = 1..10000</a>
%p N:= 10000: # to get all terms <= N
%p V:= Vector(N, n -> StringTools:-RegMatch("59|95",convert(n,string))):
%p select(t -> V[t] and not V[t-1], [$2..N]); # _Robert Israel_, Dec 11 2015
%t 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 *)
%Y Cf. A044034 (similar but with k+1 instead).
%K nonn,base
%O 1,1
%A _Clark Kimberling_
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