OFFSET
1,3
EXAMPLE
a(7) != 120*1, 120*2, ..., 120*6 as the ratios 1,2,3,...,6 appeared as 1/1, 2/1, 6/2, 24/6, 120/24, 6/1. So a(7) = 7*120 = 840.
MATHEMATICA
f[l_List] := Block[{n = Length[l], w, k = 1, r = l[[ -1]]/l}, w = Flatten[Table[Take[l, i - n]/l[[i]], {i, n}]]; While[Intersection[w, k*r] != {}, k++ ]; Append[l, k*l[[ -1]]]]; Nest[f, {1}, 21] (* Ray Chandler, Feb 08 2007 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Amarnath Murthy, Feb 19 2003
EXTENSIONS
Corrected and extended by Fung Cheok Yin (cheokyin_restart(AT)yahoo.com.hk), Sep 30 2006
Edited and further extended by Ray Chandler, Feb 08 2007
STATUS
approved