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

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

1,1

Comments

Intersection of A165561 and A229269.

Links

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

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);

Crossrefs

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

Sequence in context: A171156 A235690 A271568 * A088711 A154774 A162708

Adjacent sequences: A229268 A229269 A229270 * A229272 A229273 A229274

Keyword

nonn

Author

Paolo P. Lava, Sep 18 2013

Status

approved