A174801 Prime(n)+1 is prime or semiprime.

1, 2, 3, 6, 12, 18, 21, 37, 44, 59, 65, 78, 82, 88, 100, 112, 121, 122, 130, 134, 151, 168, 183, 191, 197, 198, 203, 216, 221, 231, 257, 260, 273, 287, 295, 301, 306, 322, 347, 366, 375, 378, 407, 415, 422, 438, 455, 459, 466, 491, 521, 556, 560, 574, 585, 587

Offset: 1

Author

Juri-Stepan Gerasimov, Mar 29 2010

Keywords

• nonn

Examples

			a(1)=1 because prime(1)+1=3=prime; a(2)=2 because prime(2)+1=4=semiprime; a(3)=3 because prime(3)+1=6=semiprime; a(4)=6 because prime(6)+1=14=semiprime.
		

Crossrefs

Cf. A000040, A001358.

Extensions

Extended by Ray Chandler, Apr 06 2010