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%I #8 Jan 24 2021 14:55:08
%S 83,373,1543,2393,4723,13997,18047,38039,43777,62801,56383,95803,
%T 109433,122701,173687,268973,250949,359441,363619,430589,832331,
%U 813797,932749,925273,1052719,1356499,1235821,1466519,1598507,1644497,1789391,1987849,3401831,3079553,2706679,3551921,3571741,5041723
%N a(n) is the least prime of the form Sum_{1<=i<=2*n-1} prime(i+1)*prime(i+k)
%H Robert Israel, <a href="/A340861/b340861.txt">Table of n, a(n) for n = 2..10000</a>
%e a(2) = 3*3+5*5+7*7 = 83 is prime.
%e a(3) = 3*3+5*5+7*7+11*11+13*13 = 373 is prime.
%e a(4) = 3*7+5*11+7*13+11*17+13*19+17*23+19*29 = 1543 is prime.
%p f:= proc(n) local B,C,i,k,t;
%p B:= [seq(ithprime(i),i=2..2*n)];
%p C:= [seq(ithprime(i),i=1..2*n-1)];
%p for k from 1 do
%p t:= add(B[i]*C[i],i=1..2*n-1);
%p if isprime(t) then return t fi;
%p C:= [op(C[2..-1]),nextprime(C[-1])];
%p od
%p end proc:
%p map(f, [$2..100]);
%K nonn
%O 2,1
%A _J. M. Bergot_ and _Robert Israel_, Jan 24 2021
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