OFFSET
1,2
COMMENTS
EXAMPLE
2+1 = 3, which is prime, so 1 is a term.
2+1 + 3+2 + 5+3 + 7+4 + 11+5 = 43, which is prime, so 5 is a term.
MAPLE
P:= [seq(ithprime(i), i=1..1000)]:
S:= ListTools:-PartialSums(P):
select(i -> isprime(S[i]+i*(i+1)/2), [$1..1000]); # Robert Israel, Sep 10 2023
MATHEMATICA
With[{m = 600}, Position[Accumulate[Range[m] + Prime[Range[m]]], _?PrimeQ] // Flatten] (* Amiram Eldar, Sep 10 2023 *)
PROG
(PARI) isok(k) = isprime(sum(i=1, k, i+prime(i))); \\ Michel Marcus, Sep 14 2023
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Saish S. Kambali, Sep 10 2023
STATUS
approved