cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A024193 Integer part of (3rd elementary symmetric function of S(n))/(2nd elementary symmetric of S(n)), where S(n) = {3,4, ..., n+4}.

Original entry on oeis.org

1, 2, 4, 7, 9, 12, 15, 19, 23, 27, 32, 36, 42, 47, 53, 59, 66, 73, 80, 88, 95, 104, 112, 121, 130, 140, 150, 160, 171, 182, 193, 204, 216, 228, 241, 254, 267, 281, 295, 309, 323, 338, 353
Offset: 1

Views

Author

Keywords

Examples

			For n=2, the 3rd elementary symmetric function of (3,4,5,6) is 3*4*5 + 3*4*6 + 3*5*6 + 4*5*6 = 342, and the 2nd elementary symmetric function of (3,4,5,6) is 3*4 + 3*5 + 3*6 + 4*5 + 4*6 + 5*6 = 119.  So 342/119 = 2.8739..., and a(2) = 2. - _Michael B. Porter_, May 05 2018
		

Crossrefs

Programs

  • Mathematica
    Table[Floor[1/2 x (7 + x) (46 + 13 x + x^2)/(144 + 41 x + 3 x^2)], {x, 43}] (* Ivan Neretin, May 02 2018 *)

Formula

a(n) = floor(A024184(n)/A024183(n+1)). - R. J. Mathar, Sep 23 2016
a(n) = floor(1/2 n (7 + n) (46 + 13 n + n^2)/(144 + 41 n + 3 n^2)). - Ivan Neretin, May 17 2018