A119646 a(n) = maximum number of partitions of n into 3 parts, each having the same product.

1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 1, 2, 2, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 2, 2, 2, 2, 2, 3, 2, 2, 2, 3, 2, 2, 2, 3, 2, 2, 2, 2, 2, 2, 2, 2, 3, 2, 3, 3, 2, 2, 2, 2, 3, 3, 2, 2, 3, 3, 3, 3, 3, 3, 2, 3, 3, 3, 3, 3, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 2, 3, 3, 3, 3, 3, 2, 3, 3, 3, 3, 3, 3

Offset: 3

Author

Joseph Biberstine (jrbibers(AT)indiana.edu) and Robert G. Wilson v, Jul 27 2006

Keywords

• nonn

Examples

			a(3)=1, because there is only one way to partition 3.
a(13)=2, because 13 = 6+6+1 = 9+2+2 and 6*6*1 = 9*2*2 = 36.
a(39)=3, because 39 = 20+15+4 = 24+10+5 = 25+8+6 and 20*15*4 = 24*10*5 = 25*8*6 = 1200.
See A103277 for more examples.
		

Crossrefs

Cf. A103277, A119028.

Programs

Mathematica

pdt[lst_] := lst[[1]]*lst[[2]]*lst[[3]];
tanya[n_] := Max[Length /@ Split[Sort[pdt /@ Union[ Partition[Last /@ Flatten[ FindInstance[a + b + c == n && a >= b >= c > 0, {a, b, c}, Integers,(* failsafe *) Round[n^2/12]]], 3]] ]]];
Table[ tanya@n, {n, 4, 108}]
Table[SortBy[Tally[Times@@@IntegerPartitions[n,{3}]],Last][[-1,2]],{n,3,110}] (* Harvey P. Dale, Jan 08 2023 *)

Extensions

Name clarified by Dmitry Kamenetsky, Aug 02 2015