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!)
 A267291 Primes which are at 2/3 of the distance between their neighbors. 1
 11, 17, 41, 71, 97, 101, 107, 197, 227, 281, 311, 397, 457, 461, 487, 499, 617, 769, 827, 857, 881, 937, 1091, 1301, 1427, 1447, 1451, 1487, 1543, 1567, 1579, 1667, 1697, 1787, 1871, 1877, 1901, 1997, 2087, 2141, 2381, 2411, 2539, 2609, 2617, 2687, 2707, 2711, 2749, 2801, 3019, 3061, 3109, 3167, 3181, 3203, 3217, 3257 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Or: primes p such that p = (prevprime(p) + 2 nextprime(p))/3, Or, p=prime(k) such that prime(k)-prime(k-1) = 2(prime(k+1)-prime(k)). See A194581 for primes which are at 1/3 of the distance between their neighbors. LINKS EXAMPLE 11 is in the sequence because 11 = (7 + 2*13) / 3. MATHEMATICA Select[Prime@ Range@ 480, # == (NextPrime[#, -1] + 2 NextPrime@ #)/3 &] (* Michael De Vlieger, Jan 12 2016 *) PROG (PARI) a(n, show=0, o=2, g=0)={forprime(p=o+1, , g==2*(g=-o+o=p)||next; show&&print1(p-g", "); n--||return(p-g))} \\ 2nd & 3rd optional args allow printing the whole list and using another starting value. CROSSREFS Cf. A194581. Sequence in context: A147253 A201476 A057473 * A073649 A178070 A243222 Adjacent sequences:  A267288 A267289 A267290 * A267292 A267293 A267294 KEYWORD nonn AUTHOR M. F. Hasler, Jan 12 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 September 26 16:43 EDT 2020. Contains 337374 sequences. (Running on oeis4.)