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 A213677 Numbers n such that n and n + 12 are prime and there is a power of two in the interval (n, n+12). 1
 5, 7, 11, 29, 31, 59, 61, 127, 251, 509, 1019, 1021, 262139, 1048571, 2147483647 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS It is a conjecture that this is a finite sequence. A search was conducted out to 2^1500. LINKS Table of n, a(n) for n=1..15. PROG (Magma) //Program finds primes separated by an even number (called gap) which //have a power of two between them. Program starts with the smallest //power of two above gap. Primes less than this starting point can be //checked by inspection. gap:=12; start:=Ilog2(gap)+1; for i:= start to 1000 do powerof2:=2^i; for k:=powerof2-gap+1 to powerof2-1 by 2 do if (IsPrime(k) and IsPrime(k+gap)) then k; end if; end for; end for; CROSSREFS A046133, A221211. Sequence in context: A106330 A057247 A157437 * A330775 A340750 A031134 Adjacent sequences: A213674 A213675 A213676 * A213678 A213679 A213680 KEYWORD nonn AUTHOR Brad Clardy, Mar 04 2013 STATUS approved

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Last modified September 23 09:36 EDT 2023. Contains 365544 sequences. (Running on oeis4.)