OFFSET
1,1
FORMULA
a(n) = a(n - 1) + lcm(n, a(n - 1)); f(n) = (a(n)/a(n - 1) - 1) + (a(n + 1)/a(n) - 1).
MATHEMATICA
a[1] = 1; a[n_] := a[n] = a[n - 1] + LCM[n, a[n - 1]]; Table[(a[n]/a[n - 1] - 1) + (a[n + 1]/a[n] - 1), {n, 2, 100}];
CROSSREFS
KEYWORD
nonn
AUTHOR
Roger L. Bagula, Nov 03 2008
STATUS
approved