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A067059
Square array read by antidiagonals of partitions which half fill an n*k box, i.e., partitions of floor(nk/2) or ceiling(nk/2) into up to n positive integers, each no more than k.
14
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, 2, 1, 1, 1, 1, 3, 3, 3, 1, 1, 1, 1, 3, 5, 5, 3, 1, 1, 1, 1, 4, 6, 8, 6, 4, 1, 1, 1, 1, 4, 8, 12, 12, 8, 4, 1, 1, 1, 1, 5, 10, 18, 20, 18, 10, 5, 1, 1, 1, 1, 5, 13, 24, 32, 32, 24, 13, 5, 1, 1, 1, 1, 6, 15, 33, 49, 58, 49, 33, 15, 6, 1, 1, 1, 1, 6
OFFSET
0,13
COMMENTS
The number of partitions of m into up to n positive integers each no more than k is maximized for given n and k by m=floor(nk/2) or ceiling(nk/2) (and possibly some other values).
EXAMPLE
Rows start:
1, 1, 1, 1, 1, 1, ...;
1, 1, 1, 1, 1, 1, ...;
1, 1, 2, 2, 3, 3, ...;
1, 1, 2, 3, 5, 6, ...;
1, 1, 3, 5, 8, 12, ...; etc.
T(4,5)=12 since 10 can be partitioned into
5+5, 5+4+1, 5+3+2, 5+3+1+1, 5+2+2+1, 4+4+2, 4+3+3,
4+4+1+1, 4+3+2+1, 4+2+2+2, 3+3+3+1, and 3+3+2+2.
MAPLE
A067059 := proc(n, k)
local m, a1, a2 ;
a1 := 0 ;
m := floor(n*k/2) ;
for L in combinat[partition](m) do
if nops(L) <= n then
if max(op(L)) <= k then
a1 := a1+1 ;
end if ;
end if;
end do:
a2 := 0 ;
m := ceil(n*k/2) ;
for L in combinat[partition](m) do
if nops(L) <= n then
if max(op(L)) <= k then
a2 := a2+1 ;
end if ;
end if;
end do:
max(a1, a2) ;
end proc:
for d from 0 to 12 do
for k from 0 to d do
printf("%d, ", A067059(d-k, k)) ;
end do:
end do: # R. J. Mathar, Nov 13 2016
MATHEMATICA
t[n_, k_] := Length[ IntegerPartitions[ Floor[n*k/2], n, Range[k]]]; Flatten[ Table[ t[n-k , k], {n, 0, 13}, {k, 0, n}]] (* Jean-François Alcover, Jan 02 2012 *)
PROG
(Sage)
def A067059(n, k):
return Partitions((n*k)//2, max_length=n, max_part=k).cardinality()
for n in (0..9): [A067059(n, k) for k in (0..9)] # Peter Luschny, May 05 2014
CROSSREFS
As this is symmetric, rows and columns each include A000012 twice, A008619, A001971, A001973, A001975, A001977, A001979 and A001981. Diagonal is A029895. T(n, n*(n-1)) is the magic series A052456.
Sequence in context: A350889 A224697 A052307 * A049704 A047996 A227690
KEYWORD
nonn,tabl
AUTHOR
Henry Bottomley, Feb 17 2002
STATUS
approved