The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A111256 a(n) = If Prime[n+2]+Prime[n]+1 is prime then Prime[n+2]+Prime[n]+1 else Prime[n+1]+Prime[n]+1. 1
 6, 11, 17, 19, 29, 31, 41, 43, 53, 67, 73, 79, 89, 97, 107, 113, 127, 129, 139, 151, 157, 163, 181, 191, 199, 205, 211, 217, 223, 241, 259, 271, 277, 289, 307, 309, 321, 337, 347, 353, 361, 373, 389, 391, 409, 411, 439, 451, 461, 463, 473, 491, 499, 509, 521 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS A switch between two sums of primes when the alternating sum is not prime then a direct sequence prime sum is switched. LINKS MATHEMATICA a=Table[If[PrimeQ[Prime[n + 2] + Prime[n] + 1], Prime[n + 2] + Prime[n] + 1, Prime[n + 1] + Prime[n] + 1], {n, 1, 200}] CROSSREFS Sequence in context: A284293 A117800 A118847 * A315506 A315507 A315508 Adjacent sequences:  A111253 A111254 A111255 * A111257 A111258 A111259 KEYWORD nonn AUTHOR Roger L. Bagula, Nov 01 2005 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
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified September 22 17:39 EDT 2021. Contains 347607 sequences. (Running on oeis4.)