cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A239672 Product_{i=1..n} J_6(i) where J_6(i) = A069091(i).

Original entry on oeis.org

1, 63, 45864, 184923648, 2889247076352, 132512427909808128, 15589822118733106642944, 4022922418094840702998413312, 2135013202351949099169693925638144, 2101519115233451721701919767332732796928, 3722967203782973732098252983015976113725767680
Offset: 1

Views

Author

Tom Edgar, Mar 23 2014

Keywords

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.

Crossrefs

Programs

  • 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]]