A004178 Omit 3's from n.

0, 1, 2, 0, 4, 5, 6, 7, 8, 9, 10, 11, 12, 1, 14, 15, 16, 17, 18, 19, 20, 21, 22, 2, 24, 25, 26, 27, 28, 29, 0, 1, 2, 0, 4, 5, 6, 7, 8, 9, 40, 41, 42, 4, 44, 45, 46, 47, 48, 49, 50, 51, 52, 5, 54, 55, 56, 57, 58, 59, 60, 61, 62, 6, 64, 65, 66, 67, 68, 69, 70, 71, 72, 7, 74

Offset: 0

Author

N. J. A. Sloane

Keywords

• nonn
• base
• easy

Comments

a(n) = 0 when n = 0 or when n is a 3-repdigit (A002277). a(n) = n when it contains no 3 among its digits. - Alonso del Arte, Oct 16 2012

Examples

			a(13) = 1 because after deleting the 3 from its base 10 representation, we're left with 1.
a(14) = 14 because there are no 3s to delete.
		

Crossrefs

Cf. A004722, A052405.

Programs

Mathematica

Table[FromDigits[DeleteCases[IntegerDigits[n], 3]], {n, 0, 74}] (* Alonso del Arte, Oct 16 2012 *)

PARI

a(n)=subst(Pol(select(k->k-3,digits(n))),'x,10) \\ Charles R Greathouse IV, Oct 16 2012