A323513 a(n) = 1 if n and phi(n) share the same prime signature, 0 otherwise.

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

Offset

1

Comments

Characteristic function for A300216.

Links

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

Index entries for characteristic functions

Formula

a(n) = [A046523(n) == A046523(A000010(n))], where [ ] is the Iverson bracket.

Prog

(PARI)
A046523(n) = { my(f=vecsort(factor(n)[, 2], , 4), p); prod(i=1, #f, (p=nextprime(p+1))^f[i]); };  \\ From A046523.
A323513(n) = (A046523(n) == A046523(eulerphi(n)));

Crossrefs

Cf. A000010, A046523, A277906, A300216.

Cf. also A318893.

Sequence in context: A016419 A016391 A016378 * A089805 A080116 A016359

Adjacent sequences: A323510 A323511 A323512 * A323514 A323515 A323516

Keyword

nonn

Author

Antti Karttunen, Jan 18 2019

Status

approved