A133292 Period 9: repeat [1, 1, 2, 4, 7, 2, 7, 4, 2].

1, 1, 2, 4, 7, 2, 7, 4, 2, 1, 1, 2, 4, 7, 2, 7, 4, 2, 1, 1, 2, 4, 7, 2, 7, 4, 2, 1, 1, 2, 4, 7, 2, 7, 4, 2, 1, 1, 2, 4, 7, 2, 7, 4, 2, 1, 1, 2, 4, 7, 2, 7, 4, 2, 1, 1, 2, 4, 7, 2, 7, 4, 2, 1, 1, 2, 4, 7, 2, 7, 4, 2, 1, 1, 2, 4, 7, 2, 7, 4, 2, 1, 1, 2, 4, 7, 2, 7, 4, 2, 1, 1, 2, 4, 7, 2, 7, 4, 2, 1, 1, 2, 4, 7, 2

Offset

0,3

Comments

For n>0, digital roots of centered 10-gonal numbers (A062786). - Colin Barker, Jan 30 2015

For n>0, also the digital roots of central polygonal numbers (the Lazy Caterer's sequence) A000124. - Peter M. Chema, Sep 17 2016

Links

Colin Barker, Table of n, a(n) for n = 0..1000

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

Formula

G.f.: -(2*x^8+4*x^7+7*x^6+2*x^5+7*x^4+4*x^3+2*x^2+x+1) / ((x-1)*(x^2+x+1)*(x^6+x^3+1)). - Colin Barker, Apr 04 2015

a(n) = a(n-9). - Wesley Ivan Hurt, May 09 2022

Mathematica

PadRight[{}, 111, {1, 1, 2, 4, 7, 2, 7, 4, 2}] (* Harvey P. Dale, Apr 29 2012 *)

Prog

(PARI) a(n)=[1, 1, 2, 4, 7, 2, 7, 4, 2][n%9+1] \\ Charles R Greathouse IV, Jun 02 2011
(PARI) Vec(-(2*x^8+4*x^7+7*x^6+2*x^5+7*x^4+4*x^3+2*x^2+x+1)/((x-1)*(x^2+x+1)*(x^6+x^3+1)) + O(x^100)) \\ Colin Barker, Apr 04 2015

Crossrefs

Cf. A000124, A062786.

Sequence in context: A134974 A244262 A166531 * A126218 A086330 A098283

Adjacent sequences: A133289 A133290 A133291 * A133293 A133294 A133295

Keyword

nonn,easy,less

Author

Paul Curtz, Oct 17 2007

Status

approved