A032940 Numbers whose base-5 representation Sum_{i=0..m} d(i)*5^(m-i) has d(i)=0 for all odd i.

1, 2, 3, 4, 5, 10, 15, 20, 25, 26, 27, 28, 29, 50, 51, 52, 53, 54, 75, 76, 77, 78, 79, 100, 101, 102, 103, 104, 125, 130, 135, 140, 145, 250, 255, 260, 265, 270, 375, 380, 385, 390, 395, 500, 505, 510, 515, 520, 625, 626, 627, 628, 629

Offset

1,2

Links

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

Maple

f:= proc(n, j) local L, m;
  L:= convert(n, base, 5);
  m:= nops(L);
  j*add(L[i+1]*5^(2*i), i=0..m-1)
end proc:
seq(seq(seq(f(n, j), n=5^k..5^(k+1)-1), j=[1, 5]), k=0..2); # Robert Israel, Nov 15 2020

Mathematica

Join[{1, 2, 3, 4}, Select[Range[700], Union[Take[IntegerDigits[#, 5], {2, -1, 2}]]=={0}&]] (* Harvey P. Dale, Mar 09 2026 *)

Crossrefs

Cf. A007091 (numbers in base 5).

Sequence in context: A076707 A364902 A382747 * A064419 A032543 A140730

Adjacent sequences: A032937 A032938 A032939 * A032941 A032942 A032943

Keyword

nonn,base

Author

Clark Kimberling

Extensions

Definition corrected by Robert Israel, Nov 15 2020

Status

approved