OFFSET
1,1
COMMENTS
Except for 157, all terms == 1 (mod 20).
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
EXAMPLE
a(3) = 401 because 401 = 7^3 + 7^2 + 7 + 2 and 7 and 401 are prime.
MAPLE
f:= proc(p) local q;
if not isprime(p) then return NULL fi;
q:= p^3+p^2+p+2;
if isprime(q) then return q fi
end proc:
map(f, [seq(i, i=3..1000, 2)]);
CROSSREFS
KEYWORD
nonn
AUTHOR
J. M. Bergot and Robert Israel, Aug 15 2021
STATUS
approved