OFFSET
1,3
COMMENTS
For a guide to related sequences, see A204892.
EXAMPLE
1 divides C(2)-C(1) -> k=2, j=1
2 divides C(3)-C(1) -> k=3, j=1
3 divides C(3)-C(2) -> k=3, j=2
4 divides C(3)-C(1) -> k=3, j=1
5 divides C(5)-C(2) -> k=5, j=2
MATHEMATICA
s = Table[(2 n)!/(n!*(n + 1)!), {n, 1,
120}]; (* Catalan numbers *)
lk = Table[
NestWhile[# + 1 &, 1,
Min[Table[Mod[s[[#]] - s[[j]], z], {j, 1, # - 1}]] =!= 0 &], {z, 1,
Length[s]}]
Table[NestWhile[# + 1 &, 1,
Mod[s[[lk[[j]]]] - s[[#]], j] =!= 0 &], {j, 1, Length[lk]}]
(* Peter J. C. Moses, Jan 27 2012 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Clark Kimberling, Feb 01 2012
STATUS
approved