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A089145 Greatest common divisor of n^2-3 and n^2+3. 3
3, 2, 1, 6, 1, 2, 3, 2, 1, 6, 1, 2, 3, 2, 1, 6, 1, 2, 3, 2, 1, 6, 1, 2, 3, 2, 1, 6, 1, 2, 3, 2, 1, 6, 1, 2, 3, 2, 1, 6, 1, 2, 3, 2, 1, 6, 1, 2, 3, 2, 1, 6, 1, 2, 3, 2, 1, 6, 1, 2, 3, 2, 1, 6, 1, 2, 3, 2, 1, 6, 1, 2, 3, 2, 1, 6, 1, 2, 3, 2, 1, 6, 1, 2, 3, 2, 1, 6, 1, 2, 3, 2, 1, 6, 1, 2, 3, 2, 1, 6, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

LINKS

Colin Barker, Table of n, a(n) for n = 0..1000

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

FORMULA

From Colin Barker, Dec 11 2019: (Start)

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

a(n) = a(n-6) for n>5.

(End)

PROG

(PARI) g(n) = for(x=0, n, print1(gcd(x^2-3, x^2+3)", "))

(PARI) Vec((3 + 2*x + x^2 + 6*x^3 + x^4 + 2*x^5) / ((1 - x)*(1 + x)*(1 - x + x^2)*(1 + x + x^2)) + O(x^80)) \\ Colin Barker, Dec 11 2019

CROSSREFS

Sequence in context: A248033 A318254 A002130 * A324644 A134199 A323417

Adjacent sequences:  A089142 A089143 A089144 * A089146 A089147 A089148

KEYWORD

easy,nonn

AUTHOR

Cino Hilliard, Dec 05 2003

STATUS

approved

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Last modified December 1 14:10 EST 2021. Contains 349430 sequences. (Running on oeis4.)