This site is supported by donations to The OEIS Foundation.

"Email this user" was broken Aug 14 to 9am Aug 16. If you sent someone a message in this period, please send it again.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A115396 Smallest prime p such that p-/+2n are semiprimes. 0
 23, 29, 71, 17, 59, 37, 71, 41, 67, 71, 43, 109, 59, 67, 173, 83, 89, 151, 103, 89, 127, 101, 131, 113, 127, 109, 131, 113, 127, 193, 157, 157, 181, 179, 229, 163, 193, 191, 211, 223, 223, 239, 241, 211, 211, 211, 271, 281, 241, 241, 263, 307, 307, 373, 293 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Cf. A063643 Primes p such that p+/-2 are semiprimes, A117328 Primes p such that p+/-4 are semiprimes. LINKS EXAMPLE a(100)=571 because 571-2*100=371=7*53 (semiprime), 571+2*100=771=3*257 (semiprime). CROSSREFS Cf. A063643. Sequence in context: A157677 A092518 A110584 * A180538 A227217 A229176 Adjacent sequences:  A115393 A115394 A115395 * A115397 A115398 A115399 KEYWORD nonn AUTHOR Zak Seidov, Mar 08 2006 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified August 16 23:48 EDT 2017. Contains 290631 sequences.