OFFSET
0,2
COMMENTS
Number of ways of placing of 12*n indistinguishable objects into indistinguishable boxes with condition that in each box can be at most 4 objects.
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (4,-6,4,-1).
FORMULA
a(n) = 12*n^3 + 15*n^2 + 6*n + 1.
From R. J. Mathar, Jun 08 2011: (Start)
G.f.: (1 + 30*x + 39*x^2 + 2*x^3) / (x-1)^4. (End)
EXAMPLE
a(1)=34 all partitions of 1*12=12 into parts < 5 are:
[1,1,1,1,1,1,1,1,1,1,1,1],
[1,1,1,1,1,1,1,1,1,1,2],
[1,1,1,1,1,1,1,1,1,3],
[1,1,1,1,1,1,1,1,2,2],
[1,1,1,1,1,1,1,1,4],
[1,1,1,1,1,1,1,2,3],
[1,1,1,1,1,1,2,2,2],
[1,1,1,1,1,1,2,4],
[1,1,1,1,1,1,3,3],
[1,1,1,1,1,2,2,3],
[1,1,1,1,2,2,2,2],
[1,1,1,1,1,3,4],
[1,1,1,1,2,2,4],
[1,1,1,1,2,3,3],
[1,1,1,2,2,2,3],
[1,1,2,2,2,2,2],
[1,1,1,1,4,4],
[1,1,1,2,3,4],
[1,1,1,3,3,3],
[1,1,2,2,2,4],
[1,1,2,2,3,3],
[1,2,2,2,2,3],
[2,2,2,2,2,2],
[1,1,2,4,4],
[1,1,3,3,4],
[1,2,2,3,4],
[1,2,3,3,3],
[2,2,2,2,4],
[2,2,2,3,3],
[1,3,4,4],
[2,2,4,4],
[2,3,3,4],
[3,3,3,3],
[4,4,4].
MATHEMATICA
Table[12n^3 + 15n^2 + 6n + 1, {n, 0, 30}]
PROG
(Magma) [12*n^3+15*n^2+6*n+1: n in [0..30]]; // Vincenzo Librandi, Jun 16 2011
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Adi Dani, Jun 07 2011
STATUS
approved