A062533 a(n) = A000010(A014076(n)).

1, 6, 8, 12, 20, 18, 20, 24, 24, 24, 42, 32, 40, 36, 36, 48, 44, 40, 60, 54, 64, 56, 72, 60, 72, 60, 48, 72, 88, 72, 96, 110, 80, 100, 84, 108, 72, 92, 120, 112, 84, 96, 120, 104, 132, 80, 156, 108, 120, 116, 120, 144, 160, 108, 96, 132, 168, 160, 132, 180, 140, 168

Offset: 1

Author

Jason Earls, Jul 10 2001

Keywords

• easy
• nonn

Links

• G. C. Greubel, Table of n, a(n) for n = 1..1000

Crossrefs

Subset of the totients of the odds (A037225).

Cf. A000010, A014076.

Programs

Mathematica

A014076 := Select[Range[1, 350, 2], PrimeOmega[#] != 1 &]; Table[ EulerPhi[A014076[[n]]], {n, 1, 50}] (* G. C. Greubel, Sep 17 2017 *)

PARI

je=[]; forstep(n=1,301,2, if(isprime(n), n+1,je=concat(je,eulerphi(n)))); je

Python

from sympy import primepi, totient
def A062533(n):
    if n == 1: return 1
    m, k = n-1, primepi(n) + n - 1 + (n>>1)
    while m != k:
        m, k = k, primepi(k) + n - 1 + (k>>1)
    return totient(m) # Chai Wah Wu, Jul 31 2024