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A203155
(n-1)-st elementary symmetric function of {3, 3, 4, 4, 5, 5,..., Floor[(n+5)/2]}.
2
1, 6, 33, 168, 984, 5640, 37440, 246240, 1853280, 13880160, 117391680, 989936640, 9315855360, 87500528640, 907925760000, 9408462336000, 106785133056000, 1210848984576000, 14928525545472000, 183922359312384000, 2448351304261632000
OFFSET
1,2
EXAMPLE
Let esf abbreviate "elementary symmetric function". Then
0th esf of {3}: 1
1st esf of {3,3}: 3+3=6
2nd esf of {3,3,4} is 3*3+3*4+3*4=33
MATHEMATICA
f[k_] := Floor[(k + 5)/2]; t[n_] := Table[f[k], {k, 1, n}]
a[n_] := SymmetricPolynomial[n - 1, t[n]]
Table[a[n], {n, 1, 22}] (* A203155 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Clark Kimberling, Dec 29 2011
STATUS
approved