A295660 Binary weight of Euler phi: a(n) = A000120(A000010(n)).

1, 1, 1, 1, 1, 1, 2, 1, 2, 1, 2, 1, 2, 2, 1, 1, 1, 2, 2, 1, 2, 2, 3, 1, 2, 2, 2, 2, 3, 1, 4, 1, 2, 1, 2, 2, 2, 2, 2, 1, 2, 2, 3, 2, 2, 3, 4, 1, 3, 2, 1, 2, 3, 2, 2, 2, 2, 3, 4, 1, 4, 4, 2, 1, 2, 2, 2, 1, 3, 2, 3, 2, 2, 2, 2, 2, 4, 2, 4, 1, 4, 2, 3, 2, 1, 3, 3, 2, 3, 2, 2, 3, 4, 4, 2, 1, 2, 3, 4, 2, 3, 1, 4, 2, 2

Offset: 1

Author

Antti Karttunen, Nov 27 2017

Keywords

• nonn

Links

• Antti Karttunen, Table of n, a(n) for n = 1..65537
• Index entries for sequences related to binary expansion of n

Crossrefs

Cf. A000010, A000120, A175548, A293516.

Cf. A003401 (gives the positions of ones).

Programs

Mathematica

Array[DigitCount[EulerPhi@ #, 2, 1] &, 105] (* Michael De Vlieger, Nov 27 2017 *)

PARI

A295660(n) = hammingweight(eulerphi(n));

Scheme

(define (A295660 n) (A000120 (A000010 n)))

Formula

a(n) = A000120(A000010(n)).