A048485 a(n) = floor(n/2) - A048475(n).

0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 1, 1, 0, 0, 0, 0, 2, 2, 3, 3, 3, 0, 3, 1, 1, 0, 1, 1, 0, 0, 4, 3, 3, 3, 2, 1, 0, 0, 0, 0, 2, 2, 1, 1, 3, 0, 0, 0, 1, 1, 5, 3, 4, 4, 3, 5, 0, 0, 8, 1, 7, 8, 2, 11, 1, 4, 4, 10, 3, 6, 11, 7, 7, 6, 6, 5, 4, 4, 7, 3, 2, 2, 5, 1, 0, 0, 0, 3, 2, 2, 1, 1, 0, 0, 0, 1, 0, 0, 3, 3

Offset

1,17

Links

Giovanni Resta, Table of n, a(n) for n = 1..4000

Example

If n=51 then the number of divisors of the central binomial coefficient binomial(51,25) is 4608, while the maximal number of divisors of binomial(51,k) is 6144, which appears first at k=24; thus the deviation a(51) = |25-24| = 1 is small.

Mathematica

a[n_] := Block[{d = DivisorSigma[0, Binomial[n, Range[0, n/2]]]}, Floor[n/2] - Position[d, Max[d], 1, 1][[1, 1]] + 1]; Array[a, 100] (* Giovanni Resta, May 14 2018 *)

Crossrefs

Cf. A000005, A001405, A034974, A048275.

Sequence in context: A084401 A236465 A131619 * A127714 A283763 A357622

Adjacent sequences: A048482 A048483 A048484 * A048486 A048487 A048488

Keyword

nonn,look

Author

Labos Elemer

Status

approved