A070448 a(n) = n^2 mod 26.

0, 1, 4, 9, 16, 25, 10, 23, 12, 3, 22, 17, 14, 13, 14, 17, 22, 3, 12, 23, 10, 25, 16, 9, 4, 1, 0, 1, 4, 9, 16, 25, 10, 23, 12, 3, 22, 17, 14, 13, 14, 17, 22, 3, 12, 23, 10, 25, 16, 9, 4, 1, 0, 1, 4, 9, 16, 25, 10, 23, 12, 3, 22, 17, 14, 13, 14, 17, 22, 3, 12, 23, 10, 25, 16, 9, 4, 1

Offset: 0

Author

N. J. A. Sloane, May 12 2002

Keywords

• nonn
• easy

Links

• G. C. Greubel, 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, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1).

Programs

Maple

A070448:=n->n^2 mod 26: seq(A070448(n), n=0..150); # Wesley Ivan Hurt, Apr 09 2017

Mathematica

Table[Mod[n^2,26],{n,0,200}] (* Vladimir Joseph Stephan Orlovsky, Apr 23 2011 *)
PowerMod[Range[0,80],2,26] (* Harvey P. Dale, Dec 15 2014 *)

PARI

a(n)=n^2%26 \\ Charles R Greathouse IV, Apr 06 2016

Formula

G.f.: (x +4*x^2 +9*x^3 +16*x^4 +25*x^5 +10*x^6 +23*x^7 +12*x^8 +3*x^9 +22*x^10 +17*x^11 +14*x^12 +13*x^13 +14*x^14 +17*x^15 + 22*x^16 + 3*x^17 +12*x^18 +23*x^19 +10*x^20 +25*x^21 +16*x^22 +9*x^23 +4*x^24 +x^25)/(1-x^26). - Vincenzo Librandi, Dec 16 2014

a(n) = a(n-26). - G. C. Greubel, Mar 24 2016