A086518 Primes arising as the arithmetic mean of a pair of successive terms of A086517.

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

Offset

1,1

Links

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

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

Cf. A086517, A259602, A259603, A259604, A259605.

Sequence in context: A215423 A019387 A019337 * A156672 A145669 A215427

Adjacent sequences: A086515 A086516 A086517 * A086519 A086520 A086521

Keyword

nonn

Author

Amarnath Murthy, Jul 30 2003

Extensions

More terms from David Wasserman, Mar 10 2005

Status

approved