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!)
 A267289 Primes p such that (2^k)+p+(2^(k+1)) is also prime, where 2^k is the largest power of 2 smaller than p. 1
 5, 7, 13, 19, 23, 31, 41, 43, 53, 61, 71, 79, 89, 101, 137, 139, 157, 163, 173, 179, 193, 223, 229, 233, 263, 271, 281, 283, 293, 349, 383, 419, 433, 449, 461, 463, 491, 509, 547, 563, 577, 593, 601, 607, 617, 643, 677, 701, 733, 751, 757, 761, 773, 797, 811, 821, 853, 857, 863, 881, 887, 911, 937, 941, 967 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Primes p such that p + 3*A053644(p) is also prime. - Robert Israel, Jan 13 2016 LINKS Robert Israel, Table of n, a(n) for n = 1..10000 EXAMPLE p = 5: 4 + 5 + 8 = 17 (is prime). p = 7: 4 + 7 + 8 = 19 (is prime). p = 31: 16 + 31 + 32 = 79 (is prime). p = 43: 32 + 43 + 64 = 139 (is prime). p = 71: 64 + 71 + 128 = 263 (is prime). p = 89: 64 + 89 + 128 = 281 (is prime). MAPLE select(t -> isprime(t) and isprime(t + 3*2^ilog2(t)), [seq(i, i=3..10^4, 2)]); # Robert Israel, Jan 13 2016 MATHEMATICA Select[Prime@ Range@ 165, Function[k, PrimeQ[(2^k) + # + (2^(k + 1))]]@ Floor@ Log2@ # &] (* Michael De Vlieger, Jan 12 2016 *) CROSSREFS Sequence in context: A216734 A114275 A156107 * A084932 A038908 A314326 Adjacent sequences:  A267286 A267287 A267288 * A267290 A267291 A267292 KEYWORD nonn AUTHOR Emre APARI, 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 August 14 12:27 EDT 2020. Contains 336480 sequences. (Running on oeis4.)