|
|
A060680
|
|
Smallest difference between consecutive divisors of n.
|
|
38
|
|
|
1, 2, 1, 4, 1, 6, 1, 2, 1, 10, 1, 12, 1, 2, 1, 16, 1, 18, 1, 2, 1, 22, 1, 4, 1, 2, 1, 28, 1, 30, 1, 2, 1, 2, 1, 36, 1, 2, 1, 40, 1, 42, 1, 2, 1, 46, 1, 6, 1, 2, 1, 52, 1, 4, 1, 2, 1, 58, 1, 60, 1, 2, 1, 4, 1, 66, 1, 2, 1, 70, 1, 72, 1, 2, 1, 4, 1, 78, 1, 2, 1, 82, 1, 4, 1, 2, 1, 88, 1, 6, 1, 2, 1, 4
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
2,2
|
|
COMMENTS
|
a(n) = 1 if n is even and a(n) is even if n is odd.
a(n) = least m>0 such that n!+1+m and n-m are not relatively prime. - Clark Kimberling, Jul 21 2012
|
|
LINKS
|
|
|
FORMULA
|
|
|
EXAMPLE
|
For n=35, divisors={1,5,7,35}; differences={4,2,28}; a(35) = smallest difference = 2.
|
|
MAPLE
|
read("transforms") :
sort(convert(numtheory[divisors](n), list)) ;
DIFF(%) ;
min(op(%)) ;
end proc:
|
|
MATHEMATICA
|
a[n_ ] := Min@@(Drop[d=Divisors[n], 1]-Drop[d, -1])
|
|
PROG
|
(Haskell)
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|