A066788 a(n) = gcd(phi(n), n^2 + 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

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) a(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