This site is supported by donations to The OEIS Foundation.

 Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing. Other ways to donate

 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 December 12 17:59 EST 2019. Contains 329960 sequences. (Running on oeis4.)