OFFSET
1,1
LINKS
Alois P. Heinz, Table of n, a(n) for n = 1..10000
MAPLE
b:= proc(n) b(n):= `if`(n<3, 2*n-1, (h-> ceil((b(n-1)+1)/h)*h)
(ilcm(map(b, numtheory[divisors](n) minus {1, n})[]))) end:
a:= n-> b(2*n)/b(n):
seq(a(n), n=1..100); # Alois P. Heinz, May 20 2014
MATHEMATICA
b[1] = 1; b[2] = 3; b[n_] := b[n] = (Ceiling[(b[n-1]+1)/#]*#&)[LCM @@ Map[b, Most[Divisors[n]]]];
a[n_] := b[2n]/b[n];
Table[a[n], {n, 1, 80}] (* Jean-François Alcover, Mar 27 2017, after Alois P. Heinz *)
CROSSREFS
KEYWORD
nonn,look
AUTHOR
J. Lowell, May 10 2014
EXTENSIONS
More terms from Alois P. Heinz, May 10 2014
STATUS
approved