OFFSET
0,4
FORMULA
1->{1, 2} 2->{1, 3} 3->6 4->{4, 5} 5->{4, 6) 6->1
MATHEMATICA
s[1] = {1, 2}; s[2] = {1, 3}; s[3] = {6}; s[4] = {4, 5}; s[5] = {4, 6}; s[6] = {1}; t[a_] := Join[a, Flatten[s /@ a]]; p[0] = {1}; p[1] = t[{1}]; p[n_] := t[p[n - 1]] aa = Flatten[Table[p[n], {n, 0, 6}]]
CROSSREFS
KEYWORD
nonn,uned
AUTHOR
Roger L. Bagula, Apr 07 2005
STATUS
approved