%I A068307
%S A068307 0,0,0,0,0,1,1,1,2,1,2,2,2,1,3,2,4,2,3,2,5,2,5,3,5,3,7,3,7,2,6,3,9,2,8,
%T A068307 4,9,4,10,2,11,3,10,4,12,3,13,4,12,5,15,4,16,3,14,5,17,3,16,4,16,6,19,
%U A068307 3,21,5,20,6,20,2,22,5,21,6,22,5,28,5,24,7,25,4,29,5,27,8,29,5,33,4,29
%N A068307 From Goldbach problem: number of decompositions of n into a sum of three 
               primes.
%C A068307 For even n>2: a(n) = A061358(n-2). [From Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), 
               Aug 08 2009]
%H A068307 Robert G. Wilson v, <a href="b068307.txt">Table of n, a(n) for n=1..36000</
               a>
%H A068307 Wikipedia, <a href="http://en.wikipedia.org/wiki/Goldbach's_conjecture">
               Goldbach's conjecture</a>.
%t A068307 f[n_] := Block[{c = 0, lmt = PrimePi@ Floor[n/2], p, q}, Do[p = Prime@ 
               i; q = Prime@ j; r = n - p - q; If[ PrimeQ@ r && r >= p, c++ ], {i, 
               lmt}, {j, i}]; c]; Array[f, 91] (* from Robert G. Wilson v, (rgwv(AT)rgwv.com), 
               Apr 13 2008 *)
%Y A068307 Bisections: A045917, A054860. Cf. A002375, A061358, A059998.
%Y A068307 First occurrence: A139321. Records: A139322.
%Y A068307 Sequence in context: A001227 A060764 A105149 this_sequence A158946 A023645 
               A054571
%Y A068307 Adjacent sequences: A068304 A068305 A068306 this_sequence A068308 A068309 
               A068310
%K A068307 easy,nonn
%O A068307 1,9
%A A068307 Naohiro Nomoto (n_nomoto(AT)yabumi.com), Feb 24 2002
%E A068307 More terms from Vladeta Jovovic (vladeta(AT)eunet.rs), Mar 10 2002