OFFSET
2,2
LINKS
Antti Karttunen, Table of n, a(n) for n = 2..16384
EXAMPLE
a(5) = 4 because 1+16, 4+9, 9+4 and 16+1 are primes.
MATHEMATICA
Table[cnt=0; Do[If[PrimeQ[k^2+(n-k)^2], cnt++ ], {k, 1, n-1}]; cnt, {n, 2, 150}]
PROG
(PARI) A082519(n) = sum(k=1, n-1, isprime((k^2)+((n-k)^2))); \\ Antti Karttunen, Jan 22 2020
CROSSREFS
KEYWORD
nonn
AUTHOR
CHAUVIN thierry (thierry.chaun2(AT)wanadoo.fr), Apr 30 2003
EXTENSIONS
Edited and extended by T. D. Noe, Oct 15 2004
STATUS
approved