A323402 - OEIS

A323402

a(n) = 1 if A023900(n) > 0 and A000010(A023900(n)) == A023900(A000010(n)), otherwise a(n) = 0. Here A000010 is Euler totient function phi, and A023900 is its Dirichlet inverse.

1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0

(list; graph; refs; listen; history; text; internal format)

OFFSET

COMMENTS

Characteristic function of A306146.

For all i, j: A323371(i) = A323371(j) => a(i) = a(j).

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..100000

Index entries for characteristic functions

PROG

(PARI)

A023900(n) = sumdivmult(n, d, d*moebius(d)); \\ From A023900

A323402(n) = { my(k=A023900(n)); ((k>0)&&(eulerphi(k) == A023900(eulerphi(n)))); };