OFFSET
2,1
LINKS
Robert Israel, Table of n, a(n) for n = 2..10000
EXAMPLE
a(2) = 3*3+5*5+7*7 = 83 is prime.
a(3) = 3*3+5*5+7*7+11*11+13*13 = 373 is prime.
a(4) = 3*7+5*11+7*13+11*17+13*19+17*23+19*29 = 1543 is prime.
MAPLE
f:= proc(n) local B, C, i, k, t;
B:= [seq(ithprime(i), i=2..2*n)];
C:= [seq(ithprime(i), i=1..2*n-1)];
for k from 1 do
t:= add(B[i]*C[i], i=1..2*n-1);
if isprime(t) then return t fi;
C:= [op(C[2..-1]), nextprime(C[-1])];
od
end proc:
map(f, [$2..100]);
CROSSREFS
KEYWORD
nonn
AUTHOR
J. M. Bergot and Robert Israel, Jan 24 2021
STATUS
approved