A024173 Integer part of ((4th elementary symmetric function of 1,2,..,n)/(2nd elementary symmetric function of 1,2,...,n)).

0, 0, 0, 3, 9, 21, 41, 72, 119, 185, 275, 395, 549, 744, 987, 1285, 1645, 2076, 2586, 3185, 3882, 4688, 5612, 6667, 7863, 9213, 10731, 12428, 14318, 16416, 18737, 21295, 24106, 27187, 30553, 34223, 38214, 42543, 47231, 52295, 57756, 63633, 69948, 76721

Offset

2,4

Links

Ivan Neretin, Table of n, a(n) for n = 2..10000

Formula

a(n)= floor(A000915(n-3)/A000914(n-1)). - R. J. Mathar, Sep 15 2009

a(n) = floor((1/240) * (n-3) * (n-2) * (15*n^3 + 15*n^2 - 10*n - 8) / (2 + 3*n)). - Ivan Neretin, May 19 2018

Example

a(4) = floor(24/35) = 0; a(5) = floor(274/85) = 3. - R. J. Mathar, Sep 15 2009

Maple

seq(floor((1/240)*(n-3)*(n-2)*(15*n^3+15*n^2-10*n-8)/(3*n+2)), n=2..50); # Muniru A Asiru, May 19 2018

Mathematica

Table[Floor[1/240 (n - 3) (n - 2) (15 n^3 + 15 n^2 - 10 n - 8)/ (2 + 3 n)], {n, 2, 45}] (* Ivan Neretin, May 19 2018 *)

Prog

(GAP) List([2..50], n->Int((1/240)*(n-3)*(n-2)*(15*n^3+15*n^2-10*n-8)/(3*n+2))); # Muniru A Asiru, May 19 2018

Crossrefs

Sequence in context: A059774 A064999 A100135 * A097119 A374585 A146608

Adjacent sequences: A024170 A024171 A024172 * A024174 A024175 A024176

Keyword

nonn

Author

Clark Kimberling

Extensions

Offset changed to 2 by R. J. Mathar, Sep 15 2009

Status

approved