A070433 a(n) = n^2 mod 9.

0, 1, 4, 0, 7, 7, 0, 4, 1, 0, 1, 4, 0, 7, 7, 0, 4, 1, 0, 1, 4, 0, 7, 7, 0, 4, 1, 0, 1, 4, 0, 7, 7, 0, 4, 1, 0, 1, 4, 0, 7, 7, 0, 4, 1, 0, 1, 4, 0, 7, 7, 0, 4, 1, 0, 1, 4, 0, 7, 7, 0, 4, 1, 0, 1, 4, 0, 7, 7, 0, 4, 1, 0, 1, 4, 0, 7, 7, 0, 4, 1, 0, 1, 4, 0, 7, 7, 0, 4, 1, 0, 1, 4, 0, 7, 7, 0, 4, 1, 0, 1

Offset

0,3

Comments

Also decimal expansion of 4692347/333333333. - Enrique Pérez Herrero, Nov 27 2022

Links

Table of n, a(n) for n=0..100.

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

Formula

From R. J. Mathar, Apr 20 2010: (Start)

a(n) = a(n-9).

G.f.: ( -x*(1+x)*(x^6+3*x^5-3*x^4+10*x^3-3*x^2+3*x+1) ) / ( (x-1)*(1+x+x^2)*(x^6+x^3+1) ). (End)

a(n) = A010878(A000290(n)) = A010878(n^2). - Enrique Pérez Herrero, Nov 27 2022

Mathematica

Table[Mod[n^2, 9], {n, 0, 200}] (* Vladimir Joseph Stephan Orlovsky, Apr 21 2011 *)
PowerMod[Range[0, 200], 2, 9] (* Harvey P. Dale, Jun 11 2011 *)

Prog

(PARI) a(n)=[0, 1, 4, 0, 7, 7, 0, 4, 1][n%9+1] \\ Charles R Greathouse IV, Jun 11 2011
(PARI) a(n)=n^2%9 \\ Charles R Greathouse IV, Jun 11 2011

Crossrefs

Cf. A000290, A010878, A053879, A070430, A070431.

Sequence in context: A077892 A117543 A242970 * A169821 A170990 A013666

Adjacent sequences: A070430 A070431 A070432 * A070434 A070435 A070436

Keyword

nonn,easy

Author

N. J. A. Sloane, May 12 2002

Status

approved