login
A133707
Denominator of a remarkable product.
2
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 5, 5, 5, 5, 1, 5, 5, 5, 1, 1, 5, 5, 1, 1, 1, 5, 1, 1, 1, 1, 5, 5, 5, 5, 5, 25, 25, 25
OFFSET
1,76
COMMENTS
There seems to be no other denominators than 1 or 5^k.
The first 5^k terms appear respectively at positions {76,101,1351,4476,7601,...}
LINKS
FORMULA
a(n) = Product( (394-225 i+85 i^2 -15 i^3+i^4)/120, i=1..n-1 )
CROSSREFS
Sequence of numerators is in A133706.
Sequence in context: A196998 A232614 A254609 * A171372 A083945 A125563
KEYWORD
nonn,frac
AUTHOR
Olivier Gérard, Sep 20, 2007
STATUS
approved