A098853 Consider the smallest denominator q such that the Sylvester expansion of n/q has n terms. Here q has the form q = k*n+1 and we set a(n) = k.

0, 1, 2, 4, 6, 18, 36, 12, 30, 162, 18, 330, 136, 858, 1092, 198, 1470, 882, 9520, 13260, 124800, 1216, 33966, 603060, 27742, 2141898, 677586

Offset

1,3

Links

Table of n, a(n) for n=1..27.

Matthijs Coster, Some sequences.

Formula

a(n) = (A048860(n)-1)/n.

Example

a(5)=6 because 5*6+1 = 31 and 5/31 = 1/7 + 1/55 + 1/3979 + 1/23744683 + 1/1127619917796295.

Prog

(PARI) a(n)=if(n==1, q=1, q=n+1; while(1, c=1; P=n; Q=q; while(Q%P>0, c++; D=Q\P+1; P=P*D-Q; Q*=D); if(c==n, break); q+=n)); return((q-1)/n)

Crossrefs

Cf. A048860.

Sequence in context: A073664 A088174 A052930 * A023149 A085146 A066894

Adjacent sequences: A098850 A098851 A098852 * A098854 A098855 A098856

Keyword

nonn,more

Author

Matthijs Coster, Oct 11 2004

Extensions

Two more terms computed from A048860 by Max Alekseyev, Mar 08 2010

a(20)-a(27) from Robert Gerbicz, Nov 19 2010

Status

approved