OFFSET
1,1
COMMENTS
Numbers k such that A343196(k) = 1.
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
MAPLE
sopf:= proc(n) local t; add(t[1]*t[2], t=ifactors(n)[2]) end proc:
R:= NULL: count:= 0: T:= 0:
for n from 2 while count < 100 do
T:= T + sopf(n);
if isprime(T) then R:= R, n; count:= count+1 fi;
od:
R;
MATHEMATICA
Select[Range[2, 530], PrimeQ@ Total@ Flatten[ConstantArray[#1, #2] & @@@ FactorInteger[#]] &[#!] &] (* Michael De Vlieger, Apr 07 2021 *)
PROG
(Python)
from sympy import isprime, factorint
A343197_list = [n for n in range(2, 10**6) if isprime(sum(sum(p*e for p, e in factorint(i).items()) for i in range(2, n+1)))] # Chai Wah Wu, Apr 09 2021
CROSSREFS
KEYWORD
nonn
AUTHOR
J. M. Bergot and Robert Israel, Apr 07 2021
STATUS
approved