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A024178 a(n) = floor(3rd elementary symmetric function of 2,3,...,n+3)/(2+3+...+n+3)). 1
2, 11, 29, 61, 115, 196, 312, 474, 690, 971, 1331, 1781, 2335, 3010, 3820, 4782, 5916, 7239, 8771, 10535, 12551, 14842, 17434, 20350, 23616, 27261, 31311, 35795, 40745, 46190, 52162, 58696, 65824, 73581, 82005, 91131, 100997, 111644, 123110, 135436 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Ivan Neretin, Table of n, a(n) for n = 1..10000

Index entries for linear recurrences with constant coefficients, signature (4,-6,5,-5,6,-4,1).

FORMULA

G.f.: x(x^3-3x^2+3x+2)/[(1-x^3)(1-x)^4].

a(n) = floor(1/24 n (n + 1) (n^2 + 9 n + 22)). - Ivan Neretin, May 21 2018

MATHEMATICA

s[n_] := 1 + Range[n + 2]

Table[Floor[SymmetricPolynomial[3, s[n]]/SymmetricPolynomial[1, s[n]]], {n, 1,

  46}] (* _ Clark Kimberling_, 23 Sep 2016 *)

LinearRecurrence[{4, -6, 5, -5, 6, -4, 1}, {2, 11, 29, 61, 115, 196, 312}, 40] (* Harvey P. Dale, Dec 05 2018 *)

CROSSREFS

Sequence in context: A046500 A062123 A117560 * A009312 A154251 A092275

Adjacent sequences:  A024175 A024176 A024177 * A024179 A024180 A024181

KEYWORD

nonn

AUTHOR

Clark Kimberling

STATUS

approved

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Last modified March 8 01:41 EST 2021. Contains 341934 sequences. (Running on oeis4.)