A023735 Numbers with exactly 2 3's in their base-5 expansion.

18, 43, 68, 78, 83, 88, 90, 91, 92, 94, 98, 118, 143, 168, 193, 203, 208, 213, 215, 216, 217, 219, 223, 243, 268, 293, 318, 328, 333, 338, 340, 341, 342, 344, 348, 368, 378, 383, 388, 390, 391, 392, 394, 398, 403, 408, 413, 415, 416, 417, 419, 423

Offset: 1

Author

Olivier Gérard

Keywords

• nonn
• base
• easy

Links

• Nathaniel Johnston, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A023733, A023734.

Programs

Maple

seq(`if`(numboccur(3,convert(n,base,5))=2,n,NULL),n=0..450); # Nathaniel Johnston, Jun 27 2011

Mathematica

Select[ Range[ 450 ], (Count[ IntegerDigits[ #, 5 ], 3 ]==2)& ]
Select[Range[500],DigitCount[#,5,3]==2&] (* Harvey P. Dale, Mar 24 2021 *)