This site is supported by donations to The OEIS Foundation.

Thanks to everyone who made a donation during our annual appeal!
To see the list of donors, or make a donation, see the OEIS Foundation home page.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A115232 Primes p which can be written in the form 2^i + q^j where i >= 0, j >= 1, q = odd prime. 2

%I

%S 5,7,11,13,17,19,23,29,31,37,41,43,47,53,59,61,67,71,73,79,83,89,97,

%T 101,103,107,109,113,127,131,137,139,151,157,163,167,173,179,181,191,

%U 193,197,199,211,223,227,229,233,239,241,251,257,263,269,271,277,281

%N Primes p which can be written in the form 2^i + q^j where i >= 0, j >= 1, q = odd prime.

%C a(n)=A000040(n+2) for n <= 32, but A000040(35)=149 is a term of A115231;

%C A115233 is a subsequence; the union with A115231 gives all primes (A000040);

%C A006512 and A053703 are subsequences.

%t maxp = 281;

%t Union[Sort[Reap[Do[p = 2^i + q^j; If[p <= maxp && PrimeQ[p], Sow[p]], {i, 0, Log[2, maxp]//Ceiling}, {j, 1, Log[3, maxp]//Ceiling}, {q, Prime[Range[2, PrimePi[maxp]]]}]][[2, 1]]]] (* _Jean-François Alcover_, Aug 03 2018 *)

%Y Cf. A000079, A061345.

%Y Cf. A006512, A053703, A115231, A115233.

%K nonn

%O 1,1

%A _Reinhard Zumkeller_, Jan 17 2006

%E Recomputed (based on recomputation of A115230) by _R. J. Mathar_ and _Reinhard Zumkeller_, Apr 29 2010

%E Edited by _N. J. A. Sloane_, Apr 30 2010

%E Terms a(1)=2 and a(2)=3 removed from Data by _Jean-François Alcover_, Aug 03 2018

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 January 17 05:26 EST 2019. Contains 319207 sequences. (Running on oeis4.)