login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A115760 Slowest growing sequence of numbers having the prime-pairwise-average property: if i<j, (a(i)+a(j))/2 is prime. 8
3, 7, 19, 55, 139, 859, 2119, 112999, 333679, 10040119, 15363619, 548687179, 16632374359, 5733638351299 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Subsequent terms are == 19 mod 30.

Inspired by A113875 (case of prime numbers). See A113832 minimal sets of primes having the P-P-A property, A115782 primes in A115760.

Equals 2*A103828(n) + 1. - N. J. A. Sloane, Apr 28 2007. This sequence is surely infinite - see comments in A103828.

LINKS

Table of n, a(n) for n=1..14.

EXAMPLE

The pairwise averages of {3,7,19} are the primes {5,11,13}.

CROSSREFS

Cf. A113832, A113875, A115782.

Sequence in context: A183122 A104522 A175533 * A183115 A183120 A100702

Adjacent sequences:  A115757 A115758 A115759 * A115761 A115762 A115763

KEYWORD

more,nonn

AUTHOR

Zak Seidov, Jan 30 2006

EXTENSIONS

More terms from Don Reble and Giovanni Resta, Feb 15 2006

STATUS

approved

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.

License Agreements, Terms of Use, Privacy Policy. .

Last modified August 15 01:40 EDT 2020. Contains 336484 sequences. (Running on oeis4.)