

A130119


a(n) = gcd(n^2  19, 45).


0



9, 15, 5, 3, 3, 1, 15, 45, 1, 9, 3, 5, 15, 3, 1, 3, 45, 5, 9, 3, 1, 15, 15, 1, 3, 9, 5, 45, 3, 1, 3, 15, 5, 3, 9, 1, 45, 15, 1, 3, 3, 5, 15, 9, 1, 9, 15, 5, 3, 3, 1, 15, 45, 1, 9, 3, 5, 15, 3, 1, 3, 45, 5, 9, 3, 1, 15, 15, 1, 3, 9, 5, 45, 3, 1, 3, 15, 5, 3, 9, 1, 45, 15, 1, 3, 3, 5, 15, 9, 1, 9, 15, 5, 3, 3, 1, 15, 45, 1, 9, 3, 5, 15, 3, 1, 3, 45, 5, 9, 3, 1, 15
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OFFSET

1,1


COMMENTS

Has period of length 45: 9,15,5,3,3,1,15,45,1,9,3,5,15,3,1,3,45,5,9,3,1,15,15,1,3,9,5,45,3,1,3,15,5,3,9,1,45,15,1,3,3,5,15,9,1.


LINKS

Table of n, a(n) for n=1..112.


FORMULA

a(n) = gcd((7n^2+2), (2n^2+7)).


MATHEMATICA

Table[GCD[n^2  19, 45], {n, 1, 100}] (* Stefan Steinerberger, May 17 2007 *)


PROG

(PARI) a(n) = gcd(n^2  19, 45); \\ Michel Marcus, Mar 23 2016


CROSSREFS

Sequence in context: A166654 A131224 A073920 * A232395 A184048 A058957
Adjacent sequences: A130116 A130117 A130118 * A130120 A130121 A130122


KEYWORD

nonn


AUTHOR

Zak Seidov, May 14 2007, corrected May 16 2007


EXTENSIONS

Better definition from Stefan Steinerberger, May 17 2007


STATUS

approved



