A048569 Values of k for which the number of divisors of the central binomial coefficient C(k, floor(k/2)) exceeds the number of divisors of all other binomial coefficients C(k,j).

1, 2, 3, 4, 5, 6, 10, 13, 14, 15, 16, 22, 26, 29, 30, 37, 38, 39, 40, 46, 47, 48, 57, 58, 85, 86, 87, 93, 94, 95, 97, 98, 106, 107, 122, 123, 124, 125, 147, 148, 149, 150, 157, 158, 159, 178, 194, 206, 214, 219, 220, 226, 230, 232, 247, 278, 283, 284, 285, 286, 316

Offset

1,2

Comments

k is in the sequence if the number of divisors of the central binomial coefficient C(k, floor(k/2)) (i.e., C(k, k/2) for even k, and C(k,(k-1)/2) = C(k,(k+1)/2) for odd k) is greater than the number of divisors of C(k, j) for all other values of j.

Links

Table of n, a(n) for n=1..61.

Example

If n=10 and k=0..10 then A000005(binomial(10,k)) = 1, 4, 6, 16, 16, 18, 16, 16, 6, 4, 1. The maximum value of A000005(binomial(10,k)), i.e., 18 occurs only at k=5, the central coefficient. Thus 10 is in this sequence.

Crossrefs

Cf. A000005, A001405, A048274, A034974, A048570.

Sequence in context: A344826 A128945 A318533 * A033085 A332320 A349862

Adjacent sequences: A048566 A048567 A048568 * A048570 A048571 A048572

Keyword

nonn

Author

Labos Elemer

Extensions

Edited by Jon E. Schoenfield, May 19 2018

Status

approved