OFFSET
1,2
LINKS
G. C. Greubel, Table of n, a(n) for n = 1..13
FORMULA
a(1) = 1, a(2) = 7, a(n) = Product_{i=1..n-1} a(i), n >= 3.
a(1) = 1, a(2) = 7, a(n) = A000420(2^(n-3)) = 7^(2^(n-3)), n >= 3.
a(1) = 1, a(2) = 7, a(3) = 7, a(n) = (a(n-1))^2, n >= 4.
MATHEMATICA
a[1]:= 1; a[2]:= 7; a[n_]:= Product[a[j], {j, 1, n-1}]; Table[a[n], {n, 1, 12}] (* G. C. Greubel, Oct 19 2018 *)
PROG
(PARI) {a(n) = if(n==1, 1, if(n==2, 7, prod(j=1, n-1, a(j))))};
for(n=1, 10, print1(a(n), ", ")) \\ G. C. Greubel, Oct 19 2018
CROSSREFS
KEYWORD
nonn
AUTHOR
Jaroslav Krizek, Sep 17 2009
EXTENSIONS
More terms from Vincenzo Librandi, Apr 21 2010
STATUS
approved