A024181 - OEIS

%I #16 May 21 2018 08:47:57

%S 1,6,17,36,66,111,175,263,380,532,725,965,1260,1617,2045,2552,3148,

%T 3841,4642,5563,6613,7805,9151,10664,12356,14241,16334,18650,21202,

%U 24008,27083,30443,34107,38091,42414,47095,52152,57606,63476,69784,76549,83795

%N Integer part of ((4th elementary symmetric function of 2,3,...,n+4)/(2nd elementary symmetric function of 2,3,...,n+4)).

%H Ivan Neretin, <a href="/A024181/b024181.txt">Table of n, a(n) for n = 1..10000</a>

%F a(n) = floor(1/240 n (n + 1) (15 n^4 + 330 n^3 + 2765 n^2 + 10482 n + 15208)/(3 n^2 + 35 n + 104)). - _Ivan Neretin_, May 20 2018

%p SymmPolyn := proc(L::list,n::integer)

%p     local c,a,sel;

%p     a :=0 ;

%p     sel := combinat[choose](nops(L),n) ;

%p     for c in sel do

%p         a := a+mul(L[e],e=c) ;

%p     end do:

%p     a;

%p end proc:

%p A024181 := proc(n)

%p     [seq(k,k=2..n+4)] ;

%p     SymmPolyn(%,4)/SymmPolyn(%,2) ;

%p     floor(%) ;

%p end proc: # _R. J. Mathar_, Sep 23 2016

%t Table[Floor[1/240 n (n + 1) (15 n^4 + 330 n^3 + 2765 n^2 + 10482 n + 15208)/(3 n^2 + 35 n + 104)], {n, 42}] (* _Ivan Neretin_, May 20 2018 *)

%o (GAP) List([1..50],n->Int((1/240)*n*(n+1)*(15*n^4+330*n^3+2765*n^2+10482*n+15208)/(3*n^2+35*n+104))); # _Muniru A Asiru_, May 20 2018

%K nonn

%O 1,2

%A _Clark Kimberling_