OFFSET
1,2
COMMENTS
From the ternary Goldbach conjecture.
LINKS
Charles R Greathouse IV, Table of n, a(n) for n = 1..50
EXAMPLE
a(2)=3: prime(2)=3, and 3^3=27=3+5+19=3+7+17=3+11+13 (3 ways).
MATHEMATICA
Table[Length@ Select[IntegerPartitions[Prime[n]^3, {3}], And[AllTrue[#, PrimeQ], UnsameQ @@ #] &], {n, 7}] (* Michael De Vlieger, Jun 28 2017 *)
PROG
(PARI) a(n)=my(t=prime(n)^3, tp, s); forprime(p=t\3, t-4, tp=t-p; forprime(q=tp\2+1, min(tp, p-1), if(isprime(tp-q), s++))); s \\ Charles R Greathouse IV, Jul 02 2017
CROSSREFS
KEYWORD
nonn
AUTHOR
Zak Seidov, Jun 28 2017
EXTENSIONS
a(11)-a(27) from Charles R Greathouse IV, Jul 02 2017
STATUS
approved