A385580 a(n) is the number of ways to partition an n X n X n cube with four noncongruent cuboids of different volumes.
0, 0, 4, 11, 47, 77, 183, 259, 457, 599, 941, 1120, 1668, 1986, 2637, 3125, 4079, 4622, 5868, 6530, 8061, 9028, 10874, 11856, 14148, 15522, 18074, 19583, 22739, 24292, 28065, 30105, 34071, 36544, 40885, 43520, 48888, 51912, 57512, 60666, 67331, 70777, 78078
Offset: 1
Keywords
Examples
There are A384311(4) = 12 different ways to decompose a 4 X 4 X 4 cube into four noncongruent cuboids, but of those 12 ways, one partition {(4,2,1), (4,2,2), (4,3,2), (4,4,1)} contains two cuboids of volume 16 ((4,2,2) and (4,4,1)) which needs to be excluded. Therefore a(4) = 12-1 = 11.
Links
- Sean A. Irvine, Table of n, a(n) for n = 1..200
Crossrefs
Cf. A384311.
Formula
Conjecture: a(p) = A384311(p) for any prime p.
Comments