multifactorial(x,n):=genfact(x,x/n,n)$

/* Test case */
makelist(multifactorial(i,1),i,1,10);
makelist(multifactorial(i,2),i,1,10);
block(makelist(mod(i,3),i,1,10),at(%%,0=1),%%*makelist(multifactorial(i,3),i,1,10));
block(makelist(mod(i,4),i,1,10),at(%%,0=1),%%*makelist(multifactorial(i,4),i,1,10));
block(makelist(mod(i,5),i,1,10),at(%%,0=1),%%*makelist(multifactorial(i,5),i,1,10));