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A210147 Numbers expressible as 2*p+q, p and q distinct primes. 1
7, 8, 9, 11, 12, 13, 15, 16, 17, 19, 21, 23, 24, 25, 27, 28, 29, 31, 33, 35, 36, 37, 39, 40, 41, 43, 45, 47, 48, 49, 51, 53, 55, 57, 59, 60, 61, 63, 64, 65, 67, 69, 71, 73, 75, 76, 77, 79, 81, 83, 84, 85, 87, 88, 89, 91, 93, 95, 96, 97, 99, 101, 103, 105, 107 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Odd terms are of the form 4+p (p odd prime), even terms are of the form 2+2*p (p odd prime). [No: the odd term 13 =4+9 is not of that form, nor 19=4+15; see A175221 for others. - R. J. Mathar, Aug 09 2019]
LINKS
EXAMPLE
7=2*2+3, 8=2+2*3, 9=2*2+5, 11=2*2+7, 12=2+2*5, 13=2*3+7=2*5+3; 19=2*3+13=2*7+5 etc.
MATHEMATICA
Union[Flatten[{2#[[1]]+#[[2]], #[[1]]+2#[[2]]}&/@Subsets[Prime[Range[20]], {2}]]] (* Harvey P. Dale, Apr 01 2013 *)
PROG
(PARI) list(lim)=my(v=[], u); forprime(p=2, lim\2-1, u=List(); forprime(q=2, lim-2*p, if(p!=q, listput(u, 2*p+q))); v=vecsort(concat(v, Vec(u)), , 8)); v \\ Charles R Greathouse IV, Mar 22 2012
CROSSREFS
Sequence in context: A120309 A035705 A205698 * A340741 A097338 A196040
KEYWORD
nonn
AUTHOR
Zak Seidov, Mar 22 2012
STATUS
approved

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Last modified April 19 19:02 EDT 2024. Contains 371798 sequences. (Running on oeis4.)