OFFSET
0,3
COMMENTS
Also numbers without 9 as a digit.
REFERENCES
Julian Havil, Gamma, Exploring Euler's Constant, Princeton University Press, Princeton and Oxford, 2003, page 34.
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
LINKS
Nathaniel Johnston,Table of n, a(n) for n = 0..10000
M. F. Hasler,Numbers avoiding certain digits,OEIS wiki, Jan 12 2020
R. G. Wilson, V,Letter to N. J. A. Sloane, Sep. 1992
FORMULA
a(0) = 0, a(n) = 10*a(n/9) if n==0 (mod 9), a(n) = a(n-1)+1 otherwise. -Benoit Cloitre,Dec 22 2002
Sum_{n>1} 1/a(n) =A082838= 22.92067... (Kempner series). -Bernard Schott,Dec 29 2018; edited byM. F. Hasler,Jan 13 2020
MAPLE
A007095:= proc(n) local l: if(n=0)then return 0: fi: l:=convert(n, base, 9): return op(convert(l, base, 10, 10^nops(l))): end: seq(A007095(n), n=0..67); #Nathaniel Johnston,May 06 2011
MATHEMATICA
Table[ FromDigits[ IntegerDigits[n, 9]], {n, 0, 75}]
PROG
(PARI) a(n)=if(n<1, 0, if(n%9, a(n-1)+1, 10*a(n/9)))
(PARI)A007095(n)=fromdigits(digits(n, 9)) \\Michel Marcus,Dec 29 2018
(Magma) [ n: n in [0..74] | not 9 in Intseq(n) ]; //Bruno Berselli,May 28 2011
(sh) seq 0 1000 | grep -v 9; #Joerg Arndt,May 29 2011
(Haskell)
a007095 = f. subtract 1 where
f 0 = 0
f v = 10 * f w + r where (w, r) = divMod v 9
--Reinhard Zumkeller,Oct 07 2014, Dec 29 2011
(Python) # and others: see OEIS Wiki page (cf. LINKS).
CROSSREFS
Cf.A000042(base 1),A007088(base 2),A007089(base 3),A007090(base 4),A007091(base 5),A007092(base 6),A007093(base 7),A007094(base 8);A057104,A037479.
Cf.A052382(without 0),A052383(without 1),A052404(without 2),A052405(without 3),A052406(without 4),A052413(without 5),A052414(without 6),A052419(without 7),A052421(without 8).
Cf.A082838.
KEYWORD
nonn,easy,base
STATUS
approved