A229271 Numbers k for which k + k' and k - k' are both prime, k' being the arithmetic derivative of k.

10, 14, 15, 21, 26, 33, 35, 38, 51, 65, 66, 78, 86, 93, 102, 110, 111, 123, 161, 201, 203, 206, 209, 215, 221, 230, 258, 278, 282, 321, 371, 374, 395, 398, 402, 413, 438, 470, 471, 485, 530, 533, 543, 545, 551, 590, 626, 671, 678, 698, 723, 755, 779, 803, 815

Offset: 1

Author

Paolo P. Lava, Sep 18 2013

Keywords

• nonn

Comments

Intersection of A165561 and A229269.

Links

• Paolo P. Lava, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A003415, A165561, A165562, A229269, A229270, A229272.

Programs

Maple

with(numtheory); P:=proc(q) local a,n,p; for n from 1 to q do
a:=n*add(op(2,p)/op(1,p),p=ifactors(n)[2]);
if isprime(n+a) and isprime(n-a) then print(n); fi;
od; end: P(10^5);