OFFSET
1,1
COMMENTS
Is this sequence a permutation of the positive integers?
EXAMPLE
Array begins:
5
1
2,3,6
17
34
Now these terms add up to 68. So row 6 is the divisors of 68 which do not occur earlier in the sequence. 1, 2, 17 and 34 occur in earlier rows, so row 6 is (4,68).
MATHEMATICA
f[t_] := Flatten[Append[t, Select[Divisors[Plus @@ t], FreeQ[t, # ] &]]]; Nest[f, {5}, 14] (* Ray Chandler, Jun 17 2006 *)
CROSSREFS
KEYWORD
nonn,tabf
AUTHOR
Leroy Quet, Jun 15 2006
EXTENSIONS
Extended by Ray Chandler, Jun 17 2006
STATUS
approved