A325112 Integers such that no nonzero subsequence of decimal representation is divisible by 3.

1, 2, 4, 5, 7, 8, 10, 11, 14, 17, 20, 22, 25, 28, 40, 41, 44, 47, 50, 52, 55, 58, 70, 71, 74, 77, 80, 82, 85, 88, 100, 101, 104, 107, 110, 140, 170, 200, 202, 205, 208, 220, 250, 280, 400, 401, 404, 407, 410, 440, 470, 500, 502, 505, 508, 520, 550, 580, 700

Offset

1,2

Comments

Integers whose decimal representation contains either just one nonzero digit, which == 1 or 2 (mod 3), or just two nonzero digits, which are either both == 1 (mod 3) or both == 2 (mod 3). - Robert Israel, Dec 25 2019

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Maple

F:= proc(d) local i, j, k, g;
   g:= [1, 2, 4, 5, 7, 8];
   op(sort([seq(i*10^(d-1), i=g), seq(seq(seq(i*10^(d-1) + j*10^k, j = select(t -> (t-i) mod 3 = 0, g)), k=0..d-2), i=g)]));
end proc:
seq(F(d), d=1..4); # Robert Israel, Dec 25 2019

Mathematica

With[{k = 3}, Select[Range@ 700, NoneTrue[DeleteCases[FromDigits /@ Rest@ Subsequences[IntegerDigits@ #], 0], Mod[#, k] == 0 &] &]] (* Michael De Vlieger, Mar 31 2019 *)

Crossrefs

Cf. A014261 (for 2), A325113 (for 4), A261189 (for 5), A325114 (for 7).

A261188 is a subsequence.

Sequence in context: A213539 A190849 A277121 * A370277 A102338 A285401

Adjacent sequences: A325109 A325110 A325111 * A325113 A325114 A325115

Keyword

nonn,base

Author

Jonathan Kal-El Peréz, Mar 27 2019

Status

approved