A023735 - OEIS

%I #13 Mar 24 2021 18:24:53

%S 18,43,68,78,83,88,90,91,92,94,98,118,143,168,193,203,208,213,215,216,

%T 217,219,223,243,268,293,318,328,333,338,340,341,342,344,348,368,378,

%U 383,388,390,391,392,394,398,403,408,413,415,416,417,419,423

%N Numbers with exactly 2 3's in their base-5 expansion.

%H Nathaniel Johnston, <a href="/A023735/b023735.txt">Table of n, a(n) for n = 1..10000</a>

%p seq(`if`(numboccur(3,convert(n,base,5))=2,n,NULL),n=0..450); # _Nathaniel Johnston_, Jun 27 2011

%t Select[ Range[ 450 ], (Count[ IntegerDigits[ #, 5 ], 3 ]==2)& ]

%t Select[Range[500],DigitCount[#,5,3]==2&] (* _Harvey P. Dale_, Mar 24 2021 *)

%Y Cf. A023733, A023734.

%K nonn,base,easy

%O 1,1

%A _Olivier Gérard_