A131798 a(n) = the maximum value from among (d(n+1),d(n+2),d(n+3),...,d(2n)), where d(m) is the number of positive divisors of m.

2, 3, 4, 4, 4, 6, 6, 6, 6, 6, 6, 8, 8, 8, 8, 8, 8, 9, 9, 9, 9, 9, 9, 10, 10, 10, 10, 10, 10, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16

Offset

1,1

Links

Table of n, a(n) for n=1..77.

Example

For n = 10, we consider the values of (d(11),d(12),d(13),d(14),d(15),d(16),d(17),d(18),d(19),d(20)), which are (2,6,2,4,4,5,2,6,2,6). The greatest of these values is 6, so a(10) = 6.

Mathematica

Table[Max[Table[Length[Divisors[i]], {i, n + 1, 2*n}]], {n, 1, 80}] (* Stefan Steinerberger, Oct 30 2007 *)

Crossrefs

Sequence in context: A342731 A099777 A221917 * A206925 A339363 A377910

Adjacent sequences: A131795 A131796 A131797 * A131799 A131800 A131801

Keyword

nonn

Author

Leroy Quet, Oct 23 2007

Extensions

More terms from Stefan Steinerberger, Oct 30 2007

Status

approved