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A168183 Numbers that are not multiples of 9. 5
1, 2, 3, 4, 5, 6, 7, 8, 10, 11, 12, 13, 14, 15, 16, 17, 19, 20, 21, 22, 23, 24, 25, 26, 28, 29, 30, 31, 32, 33, 34, 35, 37, 38, 39, 40, 41, 42, 43, 44, 46, 47, 48, 49, 50, 51, 52, 53, 55, 56, 57, 58, 59, 60, 61, 62, 64, 65, 66, 67, 68, 69, 70, 71, 73, 74, 75, 76, 77, 78, 79, 80 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

A168182(a(n)) = 1; complement of A008591;

A010888(a(n)) = A010887(n-1);

A109012(a(n)) < 9.

LINKS

Ivan Panchenko, Table of n, a(n) for n = 1..200

Index entries for linear recurrences with constant coefficients, signature (1,0,0,0,0,0,0,1,-1).

FORMULA

From Wesley Ivan Hurt, Sep 12 2015: (Start)

a(n) = a(n-1) + a(n-8) - a(n-9), n>9.

a(n) = n + floor((n-1)/8). (End)

From Philippe Deléham, Dec 05 2016: (Start)

a(n) = 1 + A248375(n-1).

G.f.: x*(1-x^9)/((1-x)^2*(1-x^8)). (End)

MAPLE

A168183:=n->n+floor((n-1)/8): seq(A168183(n), n=1..100); # Wesley Ivan Hurt, Sep 12 2015

MATHEMATICA

Select[Table[n, {n, 200}], Mod[#, 9]!=0&] (* Vladimir Joseph Stephan Orlovsky, Feb 18 2011 *)

With[{nn=81}, Complement[Range[nn], 9Range[Floor[nn/9]]]] (* Harvey P. Dale, Sep 07 2011 *)

PROG

(Haskell)

a168183 n = a168183_list !! (n-1)

a168183_list = [1..8] ++ map (+ 9) a168183_list

-- Reinhard Zumkeller, Mar 04 2014

(PARI) is(n)=!!(n%9) \\ Charles R Greathouse IV, Sep 02 2015

(PARI) a(n)=(9*n-1)\8 \\ Charles R Greathouse IV, Sep 02 2015

(MAGMA) [n+Floor((n-1)/8) : n in [1..100]]; // Wesley Ivan Hurt, Sep 12 2015

(Python) from gmpy2 import f_mod

[n for n in xrange(100) if f_mod(n, 9)] # Bruno Berselli, Dec 05 2016

CROSSREFS

Cf. A008591, A010887, A010888, A109012, A168182.

Sequence in context: A194151 A020663 A255808 * A043094 A023803 A122132

Adjacent sequences:  A168180 A168181 A168182 * A168184 A168185 A168186

KEYWORD

nonn,easy

AUTHOR

Reinhard Zumkeller, Nov 30 2009

STATUS

approved

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Last modified November 20 00:42 EST 2017. Contains 294957 sequences.