

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
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,3


COMMENTS

Is this sequence bounded? For a guide to related sequences, see A204892.


LINKS

Table of n, a(n) for n=1..99.


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
Adjacent sequences: A205791 A205792 A205793 * A205795 A205796 A205797


KEYWORD

nonn


AUTHOR

Clark Kimberling, Feb 01 2012


STATUS

approved



