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A089146 Greatest common divisor of n^2 - 4 and n^2 + 4. 1
4, 1, 8, 1, 4, 1, 8, 1, 4, 1, 8, 1, 4, 1, 8, 1, 4, 1, 8, 1, 4, 1, 8, 1, 4, 1, 8, 1, 4, 1, 8, 1, 4, 1, 8, 1, 4, 1, 8, 1, 4, 1, 8, 1, 4, 1, 8, 1, 4, 1, 8, 1, 4, 1, 8, 1, 4, 1, 8, 1, 4, 1, 8, 1, 4, 1, 8, 1, 4, 1, 8, 1, 4, 1, 8, 1, 4, 1, 8, 1, 4, 1, 8, 1, 4, 1, 8, 1, 4, 1, 8, 1, 4, 1, 8, 1, 4, 1, 8, 1, 4 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

COMMENTS

Also decimal expansion of 4181/9999 = 0.418141814181...

Multiplicative with a(2) = 8, a(2^e) = 4 if e >= 2, a(p^e) = 1 otherwise. - David W. Wilson, Jun 12 2005

LINKS

Table of n, a(n) for n=0..100.

PROG

(PARI) g(n) = for(x=0, n, print1(gcd(x^2-4, x^2+4)", "))

CROSSREFS

Sequence in context: A294791 A084884 A143320 * A297402 A239666 A101512

Adjacent sequences:  A089143 A089144 A089145 * A089147 A089148 A089149

KEYWORD

easy,nonn,mult

AUTHOR

Cino Hilliard, Dec 05 2003

STATUS

approved

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Last modified November 22 08:33 EST 2019. Contains 329389 sequences. (Running on oeis4.)