OFFSET
1,1
COMMENTS
n must clearly be even.
LINKS
Nathaniel Johnston, Table of n, a(n) for n = 1..1000
EXAMPLE
4 is a term as the sum of the cubes of the first four primes is 2^3 + 3^3 + 5^3 + 7^3 = 503, which is prime.
MAPLE
with(numtheory): P:=proc(n) add(ithprime(k)^3, k=1..n): end:
A098563 := proc(n)local m: option remember: if(n=0)then return 0: fi: m:=procname(n-1)+2: while true do if(isprime(P(m)))then return m:fi: m:=m+2:od: end:
seq(A098563(n), n=1..50); # Nathaniel Johnston, Apr 21 2011
MATHEMATICA
Select[Range[1000], PrimeQ[Sum[Prime[i]^3, {i, #}]] &] (* Carl Najafi, Aug 22 2011 *)
PROG
(PARI) lista(nn) = {s = 0; ip = 0; forprime (p=1, nn, ip++; if (isprime(s+=p^3), print1(ip, ", ")); ); } \\ Michel Marcus, Aug 22 2015
CROSSREFS
KEYWORD
nonn
AUTHOR
Rick L. Shepherd, Sep 14 2004
STATUS
approved