OFFSET
1,2
COMMENTS
Original definition: a(1)=1, a(n)=n*P(n-1) if P(n-1) < n, a(n) = floor(P(n-1)/n) if n <= P(n-1), where P(n-1) = a(1) * a(2) * ... * a(n-1).
Next term a(12) = 1273391928...9197035520 ~ 1.27*10^100 has 101 digits. - M. F. Hasler, Oct 21 2014
EXAMPLE
a(4) = floor(1*2*6/4) = 3.
a(5) = floor(1*2*6*3/5) = floor(36/5) = 7.
MATHEMATICA
a[1] = 1; p[n_] := Product[a[k], {k, 1, n}]; a[n_ /; p[n-1] < n] := a[n] = n*p[n-1]; a[n_ /; n < p[n-1]] := a[n] = Floor[p[n-1]/n]; Table[a[n], {n, 1, 12}] (* Jean-François Alcover, Jul 22 2013 *)
PROG
(PARI) a(n)=if(n<4, n!, P=3!; for(i=3, n-1, P*=P\i); P\n) \\ M. F. Hasler, Oct 21 2014
CROSSREFS
KEYWORD
nice,nonn,easy
AUTHOR
Amarnath Murthy, Oct 29 2002
EXTENSIONS
Corrected and extended by Antonio G. Astudillo (afg_astudillo(AT)lycos.com), Apr 20 2003
Edited by M. F. Hasler, Oct 21 2014
STATUS
approved