A324650 - OEIS

A324650

a(n) = A000010(A276086(n)).

1, 1, 2, 2, 6, 6, 4, 4, 8, 8, 24, 24, 20, 20, 40, 40, 120, 120, 100, 100, 200, 200, 600, 600, 500, 500, 1000, 1000, 3000, 3000, 6, 6, 12, 12, 36, 36, 24, 24, 48, 48, 144, 144, 120, 120, 240, 240, 720, 720, 600, 600, 1200, 1200, 3600, 3600, 3000, 3000, 6000, 6000, 18000, 18000, 42, 42, 84, 84, 252, 252, 168, 168, 336, 336, 1008, 1008

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OFFSET

0,3

COMMENTS

Terms are duplicated because phi(2*(2n+1)) = phi(2n+1) for all n >= 0.

LINKS

Antti Karttunen, Table of n, a(n) for n = 0..2310

Index entries for sequences related to primorial base

Index entries for sequences related to primorial numbers

FORMULA

a(n) = A000010(A276086(n)).

a(2n+1) = a(2n) for all n >= 0.

For n >= 1, a(A002110(n-1)) = A000040(n)-1.

PROG

(PARI) A324650(n) = { my(i=0, m=1, pr=1, nextpr); while((n>0), i=i+1; nextpr = prime(i)*pr; if((n%nextpr), m *= (prime(i)-1)*(prime(i)^(((n%nextpr)/pr)-1)); n-=(n%nextpr)); pr=nextpr); (m); };

(PARI)

A276086(n) = { my(i=0, m=1, pr=1, nextpr); while((n>0), i=i+1; nextpr = prime(i)*pr; if((n%nextpr), m*=(prime(i)^((n%nextpr)/pr)); n-=(n%nextpr)); pr=nextpr); m; };

A324650(n) = eulerphi(A276086(n));

CROSSREFS

Cf. A000010, A002110, A276086, A324651 (bisection).

Cf. also A267263, A276150, A324653, A324655 for omega, bigomega, sigma and tau analogs.

Cf. also A290077.

Sequence in context: A229980 A184158 A060779 * A029594 A320191 A320190

Adjacent sequences: A324647 A324648 A324649 * A324651 A324652 A324653

KEYWORD

nonn

AUTHOR

Antti Karttunen, Mar 10 2019

STATUS

approved