OFFSET
1,1
FORMULA
Equals the ordered set {k: A374941(k) = k}.
EXAMPLE
12 is a term because A374941(12) = 12.
PROG
(PARI) f(n) = my(d=divisors(n)); sum(i=2, #d-1, if (isprime(d[i]), d[i], f(d[i])));
isok(k) = f(k) == k; \\ Michel Marcus, Mar 10 2024
(Python)
from sympy import divisors, isprime
from functools import cache
@cache
def f(n): return sum(di if isprime(di) else f(di) for di in divisors(n)[1:-1])
def ok(n): return n == f(n)
print([k for k in range(1, 1000) if ok(k)]) # Michael S. Branicky, Mar 31 2024 after Michel Marcus
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Tanmaya Mohanty, Mar 10 2024
EXTENSIONS
a(13) from Michael S. Branicky, Mar 31 2024
STATUS
approved