

A071335


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


7



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

1,5


COMMENTS

a(n) = A010051(n) + A061358(n) + A068307(n). [From Reinhard Zumkeller, Aug 08 2009]


LINKS

T. D. Noe, Table of n, a(n) for n=1..10000


EXAMPLE

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


MATHEMATICA

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


CROSSREFS

Cf. A002375, A068307, A025583.
Sequence in context: A097849 A100678 A026834 * A176839 A179844 A076223
Adjacent sequences: A071332 A071333 A071334 * A071336 A071337 A071338


KEYWORD

nonn,look


AUTHOR

Reinhard Zumkeller, May 19 2002


STATUS

approved



