A174189 Numbers k such that A000040(k) +/- A163300(k) are both prime.

1, 7, 9, 12, 24, 30, 36, 63, 90, 102, 117, 126, 135, 150, 156, 165, 171, 180, 183, 225, 234, 270, 285, 369, 390, 399, 402, 447, 456, 501, 507, 537, 570, 582, 624, 627, 642, 651, 654, 660, 720, 735, 762, 777, 855, 864, 870, 885, 930, 936, 945

Offset: 1

Author

Juri-Stepan Gerasimov, Mar 11 2010

Keywords

• nonn

Examples

			a(1) = 1 because 2-0 = 2 is prime, and 2+0 = 2 is prime.
a(2) = 7 because 17-14 = 3 is prime, and 17+14 = 31 is prime.
a(3) = 9 because 23-18 = 5 is prime, and 23+18 = 41 is prime.
		

Crossrefs

Cf. A000040, A112529, A163300.

Formula

a(n) = A112529(n-1) for n >= 2. - Georg Fischer, Oct 24 2018

Extensions

Corrected (11 replaced by 12, 128 replaced by 126) and extended by R. J. Mathar, Apr 16 2010