login
A346382
Smallest k such that sum of first k primes has exactly n distinct prime divisors.
2
1, 3, 13, 53, 179, 983, 2561, 14941, 102269, 1213033, 5995117, 42509945, 331637747, 8089546229, 32698035787
OFFSET
1,2
EXAMPLE
The sum of first 3 primes 2+3+5 = 10 has exactly 2 distinct prime divisors, 3 is the smallest prime with this property, so that a(2) = 3.
PROG
(PARI) a(n) = my(k=1); while (omega(sum(i=1, k, prime(i))) != n, k++); k; \\ Michel Marcus, Jul 15 2021
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Metin Sariyar, Jul 14 2021
EXTENSIONS
a(12)-a(15) from Martin Ehrenstein, Jul 17 2021
STATUS
approved