A216100 a(n) = 11^n mod 100.

1, 11, 21, 31, 41, 51, 61, 71, 81, 91, 1, 11, 21, 31, 41, 51, 61, 71, 81, 91, 1, 11, 21, 31, 41, 51, 61, 71, 81, 91, 1, 11, 21, 31, 41, 51, 61, 71, 81, 91, 1, 11, 21, 31, 41, 51, 61, 71, 81, 91, 1

Offset

0,2

Comments

Period = 10.

Continued fraction expansion of ( 34677540795827 + sqrt(1251987878366961879130415285) ) / 64245607918014. - Bruno Berselli, Sep 14 2012

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..200

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

Formula

G.f.: (1+11*x+21*x^2+31*x^3+41*x^4+51*x^5+61*x^6+71*x^7+81*x^8+91*x^9)/((1-x)*(1+x)*(1-x+x^2-x^3+x^4)*(1+x+x^2+x^3+x^4)). - Bruno Berselli, Sep 14 2012

Mathematica

CoefficientList[Series[(1 + 11 x + 21 x^2 + 31 x^3 + 41 x^4 + 51 x^5 + 61 x^6 + 71 x^7 + 81 x^8 + 91 x^9) / ((1 - x) (1 + x) (1 - x + x^2 - x^3 + x^4) (1 + x + x^2 + x^3 + x^4)), {x, 0, 60}], x] (* Vincenzo Librandi, Jun 14 2013 *)
PowerMod[11, Range[0, 100], 100] (* or *) PadRight[{}, 100, {1, 11, 21, 31, 41, 51, 61, 71, 81, 91}] (* Harvey P. Dale, Jul 31 2023 *)

Prog

(PARI) for(i=1, 100, print(11^i%100, ", "))

Crossrefs

Cf. A001311, A014390.

Sequence in context: A225297 A123849 A108812 * A017281 A061589 A110402

Adjacent sequences: A216097 A216098 A216099 * A216101 A216102 A216103

Keyword

nonn,easy,less

Author

V. Raman, Sep 01 2012

Status

approved