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A086518 Primes arising as the arithmetic mean of a pair of successive terms of A086517. 2
2, 5, 11, 13, 17, 29, 31, 23, 29, 41, 37, 41, 53, 59, 61, 53, 59, 73, 71, 73, 83, 89, 97, 101, 97, 89, 97, 109, 113, 127, 131, 137, 131, 127, 131, 127, 137, 149, 157, 163, 173, 181, 167, 157, 167, 173, 181, 191, 193, 197, 211, 223, 229, 223, 211, 223, 241, 227, 223 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
FORMULA
a(n) = (A086517(n)+A086517(n+1))/2. - David Wasserman, Mar 10 2005
EXAMPLE
2 = (1+3)/2, 11 = (7+15)/2, etc.
PROG
(PARI) v=[1]; n=1; while(n<100, s=(n+v[#v])/2; if(type(s)=="t_INT", if(isprime(s)&&!vecsearch(vecsort(v), n), print1(s, ", "); v=concat(v, n); n=0)); n++) \\ Derek Orr, Jun 16 2015
(Haskell)
a086518 n = a086518_list !! (n-1)
a086518_list = zipWith ((flip div 2 .) . (+))
a086517_list $ tail a086517_list
-- Reinhard Zumkeller, Jun 30 2015
CROSSREFS
Sequence in context: A215423 A019387 A019337 * A156672 A145669 A215427
KEYWORD
nonn
AUTHOR
Amarnath Murthy, Jul 30 2003
EXTENSIONS
More terms from David Wasserman, Mar 10 2005
STATUS
approved

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Last modified May 23 18:13 EDT 2024. Contains 372765 sequences. (Running on oeis4.)