OFFSET
0,2
FORMULA
1->{2}, 2->{3}, 3->{1, 2, 3}
MATHEMATICA
s[1] = {2}; s[2] = {3};; s[3] = {1, 2, 3}; t[a_] := Flatten[s /@ a]; p[0] = {1}; p[1] = t[p[0]]; p[n_] := t[p[n - 1]] a = Table[Flatten[Table[If[(Length[p[i]]) >= j && (p[i][[j]] == 3), j, {}], {j, 1, i}]], {i, 1, 20}] MatrixForm[a] b = Flatten[a]
CROSSREFS
KEYWORD
nonn,uned
AUTHOR
Roger L. Bagula, Jun 09 2005
STATUS
approved