OFFSET
1,2
COMMENTS
This is the generalized factorial for A069091.
a(n) is also the determinant of the symmetric n X n matrix M defined by M(i,j) = gcd(i,j)^6 for 1 <= i,j <= n.
REFERENCES
L. Comtet, Advanced Combinatorics, Reidel, 1974, p. 203, #17.
LINKS
Antal Bege, Hadamard product of GCD matrices, Acta Univ. Sapientiae, Mathematica, 1, 1 (2009) 43-49.
Eric Weisstein's World of Mathematics, Le Paige's Theorem
PROG
(Sage)
q=15 # change q for more terms
J6=[i^6*prod([1-1/p^6 for p in prime_divisors(i)]) for i in [1..q]]
[prod(J6[0:i+1]) for i in [0..q-1]]
CROSSREFS
KEYWORD
nonn
AUTHOR
Tom Edgar, Mar 23 2014
STATUS
approved