A346382 - OEIS

A346382

Smallest k such that sum of first k primes has exactly n distinct prime divisors.

1, 3, 13, 53, 179, 983, 2561, 14941, 102269, 1213033, 5995117, 42509945, 331637747, 8089546229, 32698035787

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

OFFSET

1,2

LINKS

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

EXTENSIONS

a(12)-a(15) from Martin Ehrenstein, Jul 17 2021

STATUS

approved