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A205794
Least positive integer j such that n divides C(k)-C(j) , where k, as in A205793, is the least number for which there is such a j, and C=A002808 (composite numbers).
0
1, 1, 2, 1, 1, 1, 3, 1, 2, 1, 1, 1, 3, 1, 2, 1, 1, 1, 2, 1, 1, 1, 1, 1, 3, 1, 2, 1, 1, 1, 1, 1, 2, 1, 1, 1, 3, 1, 2, 1, 1, 1, 2, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 3, 1, 2, 1, 1, 1, 1, 1, 2, 1, 1, 1, 3, 1, 2, 1, 1, 1, 1, 1, 2, 1, 1, 1, 2, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 3, 1, 2
OFFSET
1,3
COMMENTS
Is this sequence bounded? For a guide to related sequences, see A204892.
EXAMPLE
1 divides C(2)-C(1) -> k=2, j=1
2 divides C(2)-C(1) -> k=2, j=1
3 divides C(4)-C(2) -> k=4, j=2
4 divides C(3)-C(1) -> k=3, j=1
5 divides C(4)-C(1) -> k=4, j=1
6 divides C(5)-C(1) -> k=5, j=1
MATHEMATICA
s = Select[Range[2, 120], ! PrimeQ[#] &]
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
Cf. A204892.
Sequence in context: A111604 A101491 A276949 * A241665 A175307 A324825
KEYWORD
nonn
AUTHOR
Clark Kimberling, Feb 01 2012
STATUS
approved