A337574 -id:A337574 - cp's OEIS frontend

A337573 Numbers k such that Sum_{i=1..k} prime(i)*prime(k+i) is prime.

2, 6, 26, 34, 38, 60, 102, 112, 116, 122, 140, 230, 236, 270, 300, 330, 366, 386, 418, 426, 430, 486, 488, 508, 530, 534, 548, 556, 568, 576, 600, 674, 680, 688, 696, 710, 720, 764, 772, 798, 802, 804, 824, 852, 870, 884, 906, 982, 996, 1018, 1038, 1056, 1152, 1162, 1190, 1210, 1230, 1252, 1326

Offset: 1

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J. M. Bergot and Robert Israel, Sep 01 2020

nonn

All terms are even.

Numbers k such that A337574(k) is prime.

			a(2)=6 is in the sequence because 2*17 + 3*19 + 5*23 + 7*29 + 11*31 + 13*37 = 1231 is prime.

Robert Israel, Table of n, a(n) for n = 1..8300

Cf. A000040, A337574.

P:= :
select(t -> isprime(P[1..t]^%T . P[t+1..2*t]), 2*[$1..1500]);

Select[Range[1326], PrimeQ@ Sum[Prime[i] Prime[# + i], {i, #}] &] (* Michael De Vlieger, Sep 01 2020 *)

cp's OEIS Frontend

A337573 Numbers k such that Sum_{i=1..k} prime(i)*prime(k+i) is prime.

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