|
Search: id:A115760
|
|
|
| A115760 |
|
Slowest growing sequence of numbers having the prime-pairwise-average property: if i<j, (a(i)+a(j))/2 is prime. |
|
+0
5
|
|
| 3, 7, 19, 55, 139, 859, 2119, 112999, 333679, 10040119, 15363619, 548687179, 16632374359, 5733638351299
(list; graph; listen)
|
|
|
OFFSET
|
1,1
|
|
|
COMMENT
|
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. - njas, Apr 28 2007. This sequence is surely infinite - see comments in A103828.
|
|
EXAMPLE
|
The pairwise averages of {3,7,19} are the primes {5,11,13}.
|
|
CROSSREFS
|
Cf. A113832, A113875, A115782.
Adjacent sequences: A115757 A115758 A115759 this_sequence A115761 A115762 A115763
Sequence in context: A026299 A078481 A104522 this_sequence A100702 A071716 A005506
|
|
KEYWORD
|
more,nonn
|
|
AUTHOR
|
Zak Seidov (zakseidov(AT)yahoo.com), Jan 30 2006
|
|
EXTENSIONS
|
More terms from Don Reble (djr(AT)nk.ca) and Giovanni Resta (g.resta(AT)iit.cnr.it), Feb 15 2006
|
|
|
Search completed in 0.002 seconds
|
