OFFSET
1,1
COMMENTS
Generate sum of first k primes; accept if not prime.
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
FORMULA
EXAMPLE
a(4) = 77 because 2 + 3 + 5 + 7 + 11 + 13 + 17 + 19 = 77 = A007504(8) is composite, and 77 is the 4th such composite sum of k primes.
MAPLE
N:= 10^4: # to use primes <= N
P:= select(isprime, [2, seq(i, i=3..N, 2)]):
remove(isprime, ListTools:-PartialSums(P)); # Robert Israel, Sep 22 2016
MATHEMATICA
Cases[Accumulate[Prime[Range[100]]], Except[_?PrimeQ]] (*Fred Patrick Doty Aug 22 2017*)
PROG
(PARI) first(n)=my(v=vector(n), s, i); forprime(p=2, , if(isprime(s+=p), next); v[i++]=s; if(i==n, break)); v \\ Charles R Greathouse IV, Aug 23 2017
(Python)
from sympy import isprime, nextprime
def aupto(limit):
alst, s, p = [], 2, 2
while s < limit:
if not isprime(s): alst.append(s)
p = nextprime(p)
s += p
return alst
print(aupto(6000)) # Michael S. Branicky, Oct 28 2021
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Enoch Haga, Mar 27 2000
STATUS
approved