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A066788 a(n) = gcd(phi(n), n^2 + 1). 1
1, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 5, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 10, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 5, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 10, 1, 2, 1, 2, 5, 2, 1, 2, 1, 2, 5, 2, 1, 2, 1, 10, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

Harry J. Smith, Table of n, a(n) for n = 1..1000

MATHEMATICA

Table[GCD[EulerPhi[n], n^2+1], {n, 110}] (* Harvey P. Dale, Feb 14 2018 *)

PROG

(PARI) { for (n=1, 1000, write("b066788.txt", n, " ", gcd( eulerphi(n), n^2 + 1)) ) } \\ Harry J. Smith, Mar 26 2010

CROSSREFS

Sequence in context: A347516 A322357 A160989 * A160988 A184319 A160987

Adjacent sequences:  A066785 A066786 A066787 * A066789 A066790 A066791

KEYWORD

nonn

AUTHOR

Benoit Cloitre, Jan 18 2002

STATUS

approved

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Last modified November 30 12:28 EST 2021. Contains 349419 sequences. (Running on oeis4.)