A167425 - OEIS

A167425

a(n) = 2^n mod 26.

1, 2, 4, 8, 16, 6, 12, 24, 22, 18, 10, 20, 14, 2, 4, 8, 16, 6, 12, 24, 22, 18, 10, 20, 14, 2, 4, 8, 16, 6, 12, 24, 22, 18, 10, 20, 14, 2, 4, 8, 16, 6, 12, 24, 22, 18, 10, 20, 14, 2, 4, 8, 16, 6, 12, 24, 22, 18, 10, 20, 14, 2, 4, 8, 16, 6, 12, 24, 22, 18, 10, 20, 14, 2, 4, 8, 16, 6, 12, 24

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OFFSET

0,2

LINKS

Table of n, a(n) for n=0..79.

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

FORMULA

From R. J. Mathar, Apr 13 2010: (Start)

G.f.: (x+2*x^2+4*x^3+8*x^4-10*x^5+7*x^6+13*x^7+1)/((1-x)*(x^2+1)*(x^4-x^2+1)).

a(n) = +a(n-1) -a(n-6) +a(n-7) for n>7. (End)

MATHEMATICA

PowerMod[2, Range[0, 100], 26] (* or *) PadRight[{1}, 100, {14, 2, 4, 8, 16, 6, 12, 24, 22, 18, 10, 20}] (* Harvey P. Dale, Aug 02 2013 *)