[math-fun] Permutations

20 Feb 2004

      Sum of zero moments of partitions gives A055303

{
for (i=1,8,
c=0;
for (j=1,i!,
x=numtoperm(i,j);
c+=sum(k=1,i,(k-1)*x[k]));
print1(","c))
}

Why does sum of second moments = sum of first moments of permutations of
2,3,..n?

{
for (i=1,8,
c=0;
for (j=1,i!,
x=numtoperm(i,j);
c+=sum(k=1,i,(k+1)*x[k]));
print1(","c))
}

{
for (i=1,8,
c=0;
for (j=1,i!,
x=numtoperm(i,j);
c+=sum(k=1,i,k*(x[k]+1)));
print1(","c))
}

Jon Perry
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