A130165 - OEIS

A130165

a(1)=1; a(n)=prime(mod(a(n-1),10)).

1, 2, 3, 5, 11, 2, 3, 5, 11, 2, 3, 5, 11, 2, 3, 5, 11, 2, 3, 5, 11, 2, 3, 5, 11, 2, 3, 5, 11, 2, 3, 5, 11, 2, 3, 5, 11, 2, 3, 5, 11, 2, 3, 5, 11, 2, 3, 5, 11, 2, 3, 5, 11, 2, 3, 5, 11, 2, 3, 5, 11, 2, 3, 5, 11, 2, 3, 5, 11, 2, 3, 5, 11, 2, 3, 5, 11, 2, 3, 5, 11, 2, 3, 5, 11, 2, 3, 5, 11, 2, 3, 5, 11, 2

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OFFSET

1,2

COMMENTS

Starting with the second term, cycles every four terms.

Not the same sequence as a(1)=1; a(n)=mod(prime(a(n-1)),10).

LINKS

Table of n, a(n) for n=1..94.

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

FORMULA

a(1)=1; a(n)=prime(mod(a(n-1),10)).

G.f.: x -x^2*(2+3*x+5*x^2+11*x^3) / ( (x-1)*(1+x)*(1+x^2) ). - R. J. Mathar, Jun 20 2021