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!)
 A135274 a(n) = prime(2*n) - prime(2*n-1) + prime(2*n+1). 3
 6, 13, 19, 25, 37, 47, 49, 65, 69, 77, 89, 103, 107, 113, 131, 141, 151, 159, 173, 185, 193, 199, 213, 239, 235, 247, 267, 275, 279, 287, 317, 317, 335, 353, 355, 373, 385, 393, 409, 427, 433, 441, 453, 469, 469, 499, 503, 513, 535, 565 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Original name was: Difference and sum of staircase primes according to the rule: bottom - top + next top. We list the primes in staircase fashion as follows. 2 3.5 ..7.11 ....13.17 .......19.23 ..........29.31 .............37.41 ..................... ....................n ....................n+1.n+2. The right diagonal, RD(n), is the set of top primes and the left diagonal, LD(x), is the set of bottom primes. Then a(n) = LD(n+1) - RD(n) + RD(n+2). LINKS G. C. Greubel, Table of n, a(n) for n = 1..1000 FORMULA a(n) = A181428(2*n-1). - R. J. Mathar, Sep 10 2016 MATHEMATICA Join[{6}, #[[3]]-#[[2]]+#[[4]]&/@Partition[Prime[Range[2, 110]], 4, 2]] (* Harvey P. Dale, Nov 16 2011 *) PROG (PARI) g(n) = forstep(x=1, n, 2, y=prime(x+1)-prime(x)+prime(x+2); print1(y", ")) (PARI) a(n)=prime(2*n)-prime(2*n-1)+prime(2*n+1); \\ Joerg Arndt, Oct 08 2016 CROSSREFS Sequence in context: A013575 A075727 A246306 * A189378 A022388 A041471 Adjacent sequences:  A135271 A135272 A135273 * A135275 A135276 A135277 KEYWORD nonn,easy AUTHOR Cino Hilliard, Dec 02 2007 EXTENSIONS New name from Joerg Arndt, Oct 08 2016 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 August 5 03:00 EDT 2021. Contains 346457 sequences. (Running on oeis4.)