%I #10 Aug 22 2021 22:35:27

%S 13,41,77,104,141,169,205,233,269,297,328,361,397,425,461,489,525,553,

%T 589,616,653,681,717,745,781,809,832,909,937,973,1001,1037,1065,1101,

%U 1128,1165,1193,1229,1257,1293,1321,1352,1385

%N Numbers k such that 1 and 5 occur juxtaposed in the base-8 representation of k but not of k-1.

%t j15Q[n_]:=Module[{idn8=IntegerDigits[n,8]},SequenceCount[idn8,{1,5}]>0 || SequenceCount[idn8,{5,1}]>0]; Transpose[ SequencePosition[Table[If[ j15Q[k],1,0], {k,1500}],{0,1}]][[2]] (* The program uses the SequenceCount and SequencePosition functions from Mathematica version 10 *) (* _Harvey P. Dale_, Aug 09 2015 *)

%Y Cf. A007094.

%K nonn,base

%O 1,1

%A _Clark Kimberling_