A354098 - OEIS

The OEIS is supported by the many generous donors to the OEIS Foundation.

A354098

Numbers k such that the cototient of k (= k-phi(k)) is a multiple of 4.

1, 6, 8, 12, 14, 16, 18, 20, 22, 24, 28, 32, 36, 38, 40, 44, 46, 48, 52, 54, 56, 60, 62, 64, 68, 72, 76, 80, 84, 86, 88, 92, 94, 96, 98, 100, 104, 108, 112, 116, 118, 120, 124, 128, 132, 134, 136, 140, 142, 144, 148, 152, 156, 158, 160, 162, 164, 166, 168, 172, 176, 180, 184, 188, 192, 196, 200, 204, 206, 208, 212

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

OFFSET

1,2

COMMENTS

Union of {1}, A008586 \ {0, 4} and A196445 \ {2}. - Amiram Eldar, Dec 21 2023

LINKS

Table of n, a(n) for n=1..71.

MATHEMATICA

Select[Range[200], Divisible[# - EulerPhi[#], 4] &] (* Amiram Eldar, May 17 2022 *)

PROG

(PARI)

A354097(n) = (0==((n-eulerphi(n))%4));