The OEIS is supported by the many generous donors to the OEIS Foundation.

 Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 59th year, we have over 358,000 sequences, and we’ve crossed 10,300 citations (which often say “discovered thanks to the OEIS”). Other ways to Give
 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A010878 a(n) = n mod 9. 32
 0, 1, 2, 3, 4, 5, 6, 7, 8, 0, 1, 2, 3, 4, 5, 6, 7, 8, 0, 1, 2, 3, 4, 5, 6, 7, 8, 0, 1, 2, 3, 4, 5, 6, 7, 8, 0, 1, 2, 3, 4, 5, 6, 7, 8, 0, 1, 2, 3, 4, 5, 6, 7, 8, 0, 1, 2, 3, 4, 5, 6, 7, 8, 0, 1, 2, 3, 4, 5, 6, 7, 8, 0, 1, 2, 3, 4, 5, 6, 7, 8, 0, 1, 2, 3, 4, 5, 6, 7, 8, 0, 1, 2, 3, 4, 5, 6, 7, 8, 0, 1, 2, 3, 4, 5 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 COMMENTS Periodic with period of length 9. The digital root of n (A010888) is a very similar sequence. The rightmost digit in the base-9 representation of n. Also, the equivalent value of the two rightmost digits in the base-3 representation of n. - Hieronymus Fischer, Jun 11 2007 LINKS Ely Golden, Table of n, a(n) for n = 0..10000 Index entries for linear recurrences with constant coefficients, signature (0,0,0,0,0,0,0,0,1). FORMULA Complex representation: a(n)=(1/9)*(1-r^n)*sum{1<=k<9, k*product{1<=m<9,m<>k, (1-r^(n-m))}} where r=exp(2*pi/9*i) and i=sqrt(-1). Trigonometric representation: a(n)=(256/9)^2*(sin(n*pi/9))^2*sum{1<=k<9, k*product{1<=m<9,m<>k, (sin((n-m)*pi/9))^2}}. G.f.: g(x)=(sum{1<=k<9, k*x^k})/(1-x^9). Also: g(x)=x(8x^9-9x^8+1)/((1-x^9)(1-x)^2). - Hieronymus Fischer, May 31 2007 a(n) = n mod 3 + 3*(floor(n/3)mod 3) = A010872(n) + 3*A010872(A002264(n)). - Hieronymus Fischer, Jun 11 2007 a(n) = floor(12345678/999999999*10^(n+1)) mod 10. - Hieronymus Fischer, Jan 03 2013 a(n) = floor(1513361/96855122*9^(n+1)) mod 9. - Hieronymus Fischer, Jan 04 2013 MAPLE A010878 := proc(n) modp(n, 9) ; end proc: seq(A010878(n), n=0..100) ; # R. J. Mathar, Sep 09 2015 MATHEMATICA Array[Mod[#, 9]&, 105, 0] (* Jean-François Alcover, Jan 30 2018 *) PadRight[{}, 120, Range[0, 8]] (* Harvey P. Dale, Dec 19 2018 *) PROG (Haskell) a010878 = (`mod` 9) a010878_list = cycle [0..8] -- Reinhard Zumkeller, Jan 09 2013 (PARI) a(n)=n%9 \\ Charles R Greathouse IV, Sep 24 2015 CROSSREFS Partial sums: A130487. Other related sequences A130481, A130482, A130483, A130484, A130485, A130486. Sequence in context: A207505 A235049 A031087 * A309788 A326746 A257849 Adjacent sequences: A010875 A010876 A010877 * A010879 A010880 A010881 KEYWORD nonn,easy AUTHOR STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified December 6 09:41 EST 2022. Contains 358610 sequences. (Running on oeis4.)