A351444 a(n) = n - A003958(n) + A003958(sigma(n)), where A003958 is multiplicative with a(p^e) = (p-1)^e and sigma is the sum of divisors function.

1, 3, 2, 9, 3, 6, 2, 15, 17, 10, 3, 16, 7, 10, 9, 45, 5, 38, 5, 28, 10, 16, 3, 30, 39, 26, 23, 28, 9, 26, 2, 55, 15, 26, 13, 104, 19, 28, 21, 52, 13, 32, 11, 46, 53, 28, 3, 76, 49, 94, 23, 76, 9, 54, 19, 58, 25, 46, 9, 64, 31, 34, 51, 189, 29, 50, 17, 76, 27, 50, 5, 164, 37, 74, 73, 82, 19, 66, 5, 136

Offset: 1

Author

Antti Karttunen, Feb 12 2022

Keywords

• nonn

Links

• Antti Karttunen, Table of n, a(n) for n = 1..20000
• Index entries for sequences related to sigma(n)

Crossrefs

Cf. A000203, A003958, A322582, A351442, A351445.

Cf. A351446 (fixed points), A351443 (odd terms there).

Programs

PARI

A003958(n) = { my(f = factor(n)); for(i=1, #f~, f[i, 1]--); factorback(f); };
A351444(n) = (n - A003958(n) + A003958(sigma(n)));

Formula

a(n) = A322582(n) + A351442(n) = n - A003958(n) + A003958(sigma(n)).

a(n) = n + A351445(n).