A055881 and PARI

/*
 *  Another demonstrative program: An alternative sequencer for A055881.
 *  R. J. Cano, Jan 7 2013
*/

U=3; \\ Upperbound.

default(echo,1);

output01(input01)={
  my(
    siZe1=#input01,
    siZe2=(input01[siZe1]+1)!,
    ans=vector(siZe2,k,input01[(k-1)%siZe1+1])
  );
  ans[siZe2]++;
  ans;
};

\\ print("\n\n**Please always remember pre-allocate enough mem for your task in the command line invokation.**\n\n");

v1=[1];

for(k=0,U,if(k>0,v2=output01(v1);v1=v2);print(v1));

quit();

/*
 * Acknowledgements: To M.F. Hasler and Joerg Arndt.
 *
*/