|
|
A114340
|
|
Largest palindromic divisor of n!! (double factorial = A006882(n)).
|
|
0
|
|
|
1, 2, 3, 8, 5, 8, 7, 8, 9, 8, 99, 9, 9009, 252, 9009, 252, 9009, 48384, 969969, 48384, 969969, 405504, 969969, 405504, 969969, 405504, 969969, 525525, 969969, 525525, 79833897, 525525, 133464331, 595595, 5273993725, 595595
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,2
|
|
LINKS
|
|
|
FORMULA
|
|
|
EXAMPLE
|
a(16)=252 since 252 is the largest palindromic factor of 16!!= 10321920=252* 40960.
|
|
MATHEMATICA
|
palQ[n_]:= n == FromDigits@Reverse@IntegerDigits@n; Array[Max[Select[Divisors[ #!! ], palQ]] &, 40]
|
|
CROSSREFS
|
|
|
KEYWORD
|
base,nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|