OFFSET
1,2
COMMENTS
Minimum product of hook lengths of a partition of n. - Eric M. Schmidt, May 07 2013
LINKS
Eric M. Schmidt, Table of n, a(n) for n = 1..80
Eric Weisstein's World of Mathematics, Hook Length Formula
EXAMPLE
For n=4, we can have
abcd, abc and ab (the rest are symmetric).
......d.......cd
The hook products are 4! = 24, 4*2*1*1 = 8 and 3*2*2*1 = 12, so a(4) = 8. - Jon Perry
MAPLE
# Maple code from Emeric Deutsch, May 12 2004 (Start)
H:=proc(pa) local F, j, p, Q, i, col, a, A: F:=proc(x) local i, ct: ct:=0: for i from 1 to nops(x) do if x[i]>1 then ct:=ct+1 else fi od: ct; end:
for j from 1 to nops(pa) do p[1][j]:=pa[j] od: Q[1]:=[seq(p[1][j], j=1..nops(pa))]:
for i from 2 to pa[1] do for j from 1 to F(Q[i-1]) do p[i][j]:=Q[i-1][j]-1 od:
Q[i]:=[seq(p[i][j], j=1..F(Q[i-1]))] od:
for i from 1 to pa[1] do col[i]:=[seq(Q[i][j]+ nops(Q[i])-j, j=1..nops(Q[i]))] od:
a:=proc(i, j) if i<=nops(Q[j]) and j<=pa[1] then Q[j][i]+nops(Q[j])-i else 1 fi end:
A:=matrix(nops(pa), pa[1], a): product(product(A[m, n], n=1..pa[1]), m=1..nops(pa)); end:
with(combinat):
rev:=proc(a) [seq(a[nops(a)+1-i], i=1..nops(a))] end:
seq(sort([seq(H(rev(partition(j)[i])), i=1..numbpart(j))])[1], j=1..30);
# the procedure H gives the hook product for a given partition written with parts in nonincreasing order;
# if in the definition of the procedure a we replace "else 1" by "else x", then the matrix A yields all the hooklengths corresponding to a partition.
# (End)
CROSSREFS
KEYWORD
nonn
AUTHOR
Yuval Dekel (dekelyuval(AT)hotmail.com), May 25 2003
EXTENSIONS
More terms from Eric M. Schmidt, May 07 2013
STATUS
approved