OFFSET
1,1
MATHEMATICA
Flatten[NestList[#/.(Thread[#->Range[#]]&[Range[4]])&, {4}, 8]] (* Peter J. C. Moses, Apr 15 2013 *)
PROG
(PARI) v=[4]; for(n=1, 200, for(i=1, v[n], v=concat(v, i)); v); a(n)=v[n];
CROSSREFS
KEYWORD
nonn
AUTHOR
Benoit Cloitre, Feb 18 2009
STATUS
approved