A004180 Omit 5's from n.

0, 1, 2, 3, 4, 0, 6, 7, 8, 9, 10, 11, 12, 13, 14, 1, 16, 17, 18, 19, 20, 21, 22, 23, 24, 2, 26, 27, 28, 29, 30, 31, 32, 33, 34, 3, 36, 37, 38, 39, 40, 41, 42, 43, 44, 4, 46, 47, 48, 49, 0, 1, 2, 3, 4, 0, 6, 7, 8, 9, 60, 61, 62, 63, 64, 6, 66, 67, 68, 69, 70, 71, 72, 73, 74

Offset: 0

Author

N. J. A. Sloane

Keywords

• nonn
• base
• easy

Comments

See A004724 for a variant where a(n) disappears when n has only digits 5. - M. F. Hasler, Jan 13 2020

Crossrefs

Cf. A004724.

Programs

MATLAB

for u=0:74 ; v=dec2base(u, 10)-'0'; v = v(v~=5); if length(v)>0; sol(u+1)=(str2num(strrep(num2str(v), ' ', ''))); else; sol(u+1)=0; end; end; sol % Marius A. Burtea, Jan 13 2020

Mathematica

Table[FromDigits[DeleteCases[IntegerDigits[n], 5]], {n, 0, 79}] (* Harvey P. Dale, Jan 20 2015 *)

PARI

a(n)=subst(Pol(select(k->k-5,digits(n))),'x,10) \\ Charles R Greathouse IV, Oct 16 2012

PARI

A004180(n)=fromdigits([d|d<-digits(n),d!=5]) \\ M. F. Hasler, Jan 13 2020

Scala

(0 to 99).map(n => try {
  Integer.parseInt(Integer.toString(n).replace("5", ""))
} catch {
  case _: NumberFormatException => 0
}) // Alonso del Arte, Jan 13 2020