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”).
%I #13 Jun 30 2021 03:54:39
%S 15,51,105,125,135,145,150,152,153,154,156,157,158,159,165,175,185,
%T 195,215,251,315,351,415,451,501,510,512,513,514,516,517,518,519,521,
%U 531,541,561,571,581,591,615,651,715,751,815,851,915,951,1005,1025
%N Numbers whose base-10 representation has the same nonzero number of 1's and 5's.
%t Select[Range[1100],DigitCount[#,10,1]==DigitCount[#,10,5]>0&] (* _Harvey P. Dale_, Nov 26 2020 *)
%K nonn,base,easy
%O 1,1
%A _Olivier Gérard_