A045016 Numbers whose base-4 representation contains no 0's and exactly three 1's.

21, 86, 87, 89, 93, 101, 117, 149, 213, 346, 347, 350, 351, 358, 359, 361, 365, 374, 375, 377, 381, 406, 407, 409, 413, 421, 437, 470, 471, 473, 477, 485, 501, 598, 599, 601, 605, 613, 629, 661, 725, 854, 855, 857, 861, 869, 885

Offset

1,1

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..3500

Mathematica

Select[Range[10000], DigitCount[#, 4, 0] == 0 && DigitCount[#, 4, 1] == 3 &] (* Vincenzo Librandi, Sep 21 2016 *)

Crossrefs

Cf. A007090.

Sequence in context: A217549 A063651 A220613 * A171129 A301540 A240518

Adjacent sequences: A045013 A045014 A045015 * A045017 A045018 A045019

Keyword

nonn,base

Author

Clark Kimberling

Status

approved