A043525 Numbers having one 9 in base 10.

9, 19, 29, 39, 49, 59, 69, 79, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 109, 119, 129, 139, 149, 159, 169, 179, 189, 190, 191, 192, 193, 194, 195, 196, 197, 198, 209, 219, 229, 239, 249, 259, 269, 279, 289, 290, 291, 292, 293, 294, 295, 296, 297, 298, 309, 319

Offset

1,1

Links

Enrique Pérez Herrero, Table of n, a(n) for n = 1..2000

Index entries for 10-automatic sequences.

Formula

Sum_{n>=1} 1/a(n) = A140502. - Amiram Eldar, Nov 14 2020

Mathematica

Select[Range[300], DigitCount[#, 10, 9]==1&] (* Harvey P. Dale, Jan 19 2013 *)

Prog

(Python)
def ok(n): return str(n).count('9') == 1
print(list(filter(ok, range(320)))) # Michael S. Branicky, Sep 19 2021

Crossrefs

Cf. A043489, A043493, A043497, A043501, A043505, A043509, A043513, A043517, A043521.

Cf. A011539, A140502.

Subsequence of A011539.

Sequence in context: A088923 A011539 A088479 * A277596 A031499 A017377

Adjacent sequences: A043522 A043523 A043524 * A043526 A043527 A043528

Keyword

nonn,base

Author

Clark Kimberling

Status

approved