A107797 a(n) = phi(Padovan(n+4)).

0, 1, 1, 1, 1, 1, 2, 2, 4, 6, 6, 4, 8, 12, 12, 36, 42, 48, 42, 36, 150, 80, 208, 216, 240, 240, 256, 1012, 712, 1620, 2148, 3328, 1008, 2772, 7560, 4640, 9036, 11988, 23832, 10512, 20896, 37968, 35960, 88380, 122004, 72000, 77472, 149712, 271824, 168960

Offset

0,7

Links

Table of n, a(n) for n=0..49.

Formula

a(n) = A000010(A000931(n+4)). - R. J. Mathar, Sep 11 2011

Maple

A107797 := proc(n)
        numtheory[phi](A000931(n+4)) ;
end proc:
seq(A107797(n), n=0..50) ; # R. J. Mathar, Sep 11 2011

Mathematica

(*Method one*) M = {{0, 1, 0}, {0, 0, 1}, {1, 1, 0}} v[1] = {0, 1, 1} v[n_] := v[n] = M.v[n - 1] a = Table[EulerPhi[v[n][[1]]], {n, 1, 50}] (Method two*) F[1] = 0; F[2] = 1; F[3] = 1; F[n__] := F[n] = F[n - 2] + F[n - 3] a = Table[EulerPhi[F[n]], {n, 1, 50}]

Crossrefs

Cf. A000931.

Sequence in context: A347797 A351746 A118960 * A316788 A038759 A045999

Adjacent sequences: A107794 A107795 A107796 * A107798 A107799 A107800

Keyword

nonn

Author

Roger L. Bagula, Jun 11 2005

Status

approved