login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A071335 Number of partitions of n into sum of at most three primes. 11

%I #24 Mar 28 2023 12:37:34

%S 0,1,1,1,2,2,3,2,3,3,3,3,4,3,4,4,5,4,5,4,6,5,6,6,6,6,7,5,8,5,8,5,10,6,

%T 8,8,10,6,11,5,12,7,12,7,13,7,14,9,13,9,15,7,17,8,15,8,17,7,17,10,18,

%U 9,20,8,21,11,21,8,21,7,23,11,23,11,23,10,28,12,25,11,26

%N Number of partitions of n into sum of at most three primes.

%C a(n) = A010051(n) + A061358(n) + A068307(n). [From _Reinhard Zumkeller_, Aug 08 2009]

%H T. D. Noe, <a href="/A071335/b071335.txt">Table of n, a(n) for n=1..10000</a>

%e a(21)=6 as 21 = 2+19 = 2+2+17 = 3+5+13 = 3+7+11 = 5+5+11 = 7+7+7.

%t goldbachcount[p1_] := (parts=IntegerPartitions[p1, 3]; count=0; n=1;

%t While[n<=Length[parts], If[Intersection[Flatten[PrimeQ[parts[[n]]]]][[1]]==True, count++]; n++]; count); Table[goldbachcount[i], {i, 1, 100}] (* _Frank M Jackson_, Mar 25 2013 *)

%t Table[Length[Select[IntegerPartitions[n,3],AllTrue[#,PrimeQ]&]],{n,90}] (* The program uses the AllTrue function from Mathematica version 10 *) (* _Harvey P. Dale_, Oct 21 2016 *)

%Y Cf. A002375, A068307, A025583.

%K nonn,look

%O 1,5

%A _Reinhard Zumkeller_, May 19 2002

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 24 20:08 EDT 2024. Contains 371963 sequences. (Running on oeis4.)