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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

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Last modified August 14 12:27 EDT 2020. Contains 336480 sequences. (Running on oeis4.)