A004725 Delete all 6's from the sequence of nonnegative integers.

0, 1, 2, 3, 4, 5, 7, 8, 9, 10, 11, 12, 13, 14, 15, 1, 17, 18, 19, 20, 21, 22, 23, 24, 25, 2, 27, 28, 29, 30, 31, 32, 33, 34, 35, 3, 37, 38, 39, 40, 41, 42, 43, 44, 45, 4, 47, 48, 49, 50, 51, 52, 53, 54, 55, 5, 57, 58, 59, 0, 1, 2, 3, 4, 5, 7, 8, 9, 70, 71, 72, 73, 74, 75, 7

Offset

0,3

Links

Table of n, a(n) for n=0..74.

Mathematica

d6[n_]:=Module[{c=DeleteCases[IntegerDigits[n], 6]}, If[c=={}, Nothing, FromDigits[ c]]]; Array[d6, 80, 0] (* Harvey P. Dale, Oct 09 2017 *)

Prog

(Python)
def A004725(n):
    l = len(str(n))
    m = 2*(10**l-1)//3
    k = n + l - int(n+l < m)
    return 5 if k == m else int(str(k).replace('6', '')) # Chai Wah Wu, Apr 20 2021

Crossrefs

Cf. A004719, A004720, A004721, A004722, A004723, A004724, A004726, A004727, A004728.

Sequence in context: A290019 A161924 A034153 * A129487 A097010 A351227

Adjacent sequences: A004722 A004723 A004724 * A004726 A004727 A004728

Keyword

base,nonn

Author

N. J. A. Sloane

Status

approved