A023731 Numbers with exactly two 2's in base 5 expansion.

12, 37, 52, 57, 60, 61, 63, 64, 67, 72, 87, 112, 137, 162, 177, 182, 185, 186, 188, 189, 192, 197, 212, 237, 252, 257, 260, 261, 263, 264, 267, 272, 277, 282, 285, 286, 288, 289, 292, 297, 300, 301, 303, 304, 305, 306, 308, 309

Offset

1,1

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..3000

Mathematica

Select[ Range[ 325 ], (Count[ IntegerDigits[ #, 5 ], 2 ]==2)& ]
Select[Range[400], DigitCount[#, 5, 2]==2&] (* Harvey P. Dale, Feb 13 2022 *)

Crossrefs

Sequence in context: A130164 A144973 A043358 * A045285 A045270 A012276

Adjacent sequences: A023728 A023729 A023730 * A023732 A023733 A023734

Keyword

nonn,base,easy

Author

Olivier Gérard

Status

approved