OFFSET
1,2
COMMENTS
n^k+(n+1)^k is prime only for k = power of 2.
There are 1242 terms < 10^6.
All terms > 2 are congruent to 0 or 4 (mod 5). - Robert Israel, Mar 29 2017
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
EXAMPLE
{2+1, 2^2+3^2,2^4+3^4} = {3,13,97} all prime,
{9+10, 9^2+10^2,9^4+10^4} = {19,181,16561} all prime.
MAPLE
select(n -> isprime(2*n+1) and isprime(2*n^2+2*n+1) and isprime(n^4+(n+1)^4),
[1, 2, seq(seq(5*i+j, j=[0, 4]), i=1..10000)]); # Robert Israel, Mar 29 2017
MATHEMATICA
pnQ[n_]:=And@@PrimeQ/@(n^{1, 2, 4}+(n+1)^{1, 2, 4}); Select[Range[9000], pnQ] (* Harvey P. Dale, Apr 06 2011 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Zak Seidov, Mar 28 2007
STATUS
approved