A048683 Values of n for which the difference of maximal and central squarefree kernel numbers dividing values of {C(n,k)} or A001405(n) is zero.

1, 2, 3, 4, 5, 7, 8, 9, 11, 12, 13, 16, 17, 18, 19, 23, 24, 31, 32, 33, 35, 36, 40, 41, 42, 55, 56, 57, 59, 65, 71, 72, 73, 80, 84, 100, 108, 109, 112, 113, 114, 115, 131, 132, 133, 155, 160, 161, 162, 163, 168, 183, 184, 199, 200, 201, 203, 209, 220, 224, 256

Offset

1,2

Comments

Indices of 0's in A048682. - Sean A. Irvine, Jun 26 2021

Links

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

Formula

max{sqf kernel(C(n, k)} - sqf kernel(C(n, [ n/2 ])) = 0

Example

For n=23 both the maximal and central largest-squarefree number dividing the corresponding {C(23,k)} values is 1352078=2*7*13*17*19*23=C(23,12) accidentally. The same 1352078 is the maximal-largest squarefree divisor for C(24,k) values but 1352078=C(24,12)/2. Thus both 23 and 24 are in this sequence.

Crossrefs

Analogous cases for A001221, A001222 functions as applied to {C(n, k)} are given in A020731 and A048627.

Cf. A048682.

Sequence in context: A119848 A265640 A268375 * A231876 A334298 A364160

Adjacent sequences: A048680 A048681 A048682 * A048684 A048685 A048686

Keyword

nonn

Author

Labos Elemer

Extensions

More terms from Sean A. Irvine, Jun 26 2021

Status

approved