Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A103622
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
%I A103622
%S A103622 2,4,4,7,6,11,10,13,12,17,16,21,20,24,24,29,26,32,32,36,36,41,38,45,44,
%T A103622 49,48,53,52,58,58,63,62,68,66,72,70,77,76,83,80,87,86,92,90,97,96,102,
%U A103622 100,108,106,113,110,118,116,123,122,129,126,133,132,139,138,145,142
%N A103622 Smallest arithmetic mean of n distinct primes.
%C A103622 Often a(2n+1)=a(2n)-1. - Robert G. Wilson v Jan 19 2007
%e A103622 a(1)=2 because (2)/1=2,
%e A103622 a(2)=4 because (3+5)/2=4,
%e A103622 a(3)=4 because (2+3+7)/3=4,
%e A103622 a(4)=7 because (3+5+7+13)/4=7,
%e A103622 a(5)=6 because (2+3+5+7+13)/5=6,
%e A103622 a(6)=11 because (3+5+7+11+17+23)/6=11,
%e A103622 a(7)=10 because (2+3+5+7+11+13+29)/7=10,
%e A103622 a(8)=13 because (3+5+7+11+13+17+19+29)/8=13,
%e A103622 a(9)=12 because (2+3+5+7+11+13+17+19+31)/9=12,
%e A103622 a(10)=17 because (3+5+7+11+13+17+19+23+29+43)/10=17, etc.
%t A103622 f[n_] := Block[{k = 1, lst = Prime@ Range[ If[ OddQ@ n, 1, 2], n + 3]}, 
               While[ Mod[Plus @@ Flatten@Subsets[lst, {n}, {k}], n] != 0, k++ ]; 
               (Plus @@ Flatten@ Subsets[lst, {n}, {k}])/n]; Array[f, 65] (* Robert 
               G. Wilson v *)
%Y A103622 Cf. A072701.
%Y A103622 Sequence in context: A104510 A082515 A062855 this_sequence A105774 A130805 
               A023831
%Y A103622 Adjacent sequences: A103619 A103620 A103621 this_sequence A103623 A103624 
               A103625
%K A103622 easy,nonn
%O A103622 1,1
%A A103622 Giovanni Teofilatto (g.teofilatto(AT)tiscalinet.it), Mar 25 2005
%E A103622 Edited, corrected and extended by Robert G. Wilson v (rgwv(AT)rgwv.com), 
               Jan 19 2007

    
page 1

Search completed in 0.002 seconds

Lookup | Welcome | Find friends | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
More pages | Superseeker | Maintained by N. J. A. Sloane (njas@research.att.com)

Last modified December 6 13:45 EST 2009. Contains 170429 sequences.


AT&T Labs Research