OFFSET
1,1
COMMENTS
For a guide to related sequences, see A204892.
EXAMPLE
1 divides 2*2!-2*1! -> k=2, j=1
2 divides 2*2!-2*1! -> k=2, j=1
3 divides 2*4!-2*3! -> k=4, j=3
4 divides 2*3!-2*2! -> k=3, j=2
5 divides 2*3!-2*1! -> k=3, j=1
MATHEMATICA
s = Table[2n!, {n, 1, 120}];
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