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A203230
(n-1)-st elementary symmetric function of the first n terms of A010684.
2
1, 4, 7, 24, 33, 108, 135, 432, 513, 1620, 1863, 5832, 6561, 20412, 22599, 69984, 76545, 236196, 255879, 787320, 846369, 2598156, 2775303, 8503056, 9034497, 27634932, 29229255, 89282088, 94065057, 286978140, 301327047, 918330048
OFFSET
1,2
FORMULA
Conjecture: a(n)=6*a(n-2)-9*a(n-4) with G.f. x*(1+4*x+x^2) / (-1+3*x^2)^2 . - R. J. Mathar, Oct 15 2013
MATHEMATICA
r = {1, 3, 1, 3, 1, 3};
s = Flatten[{r, r, r, r, r, r, r, r, r}];
t[n_] := Part[s, Range[n]]
a[n_] := SymmetricPolynomial[n - 1, t[n]]
Table[a[n], {n, 1, 32}] (* A203230 *)
CROSSREFS
Cf. A010684, A203231, A120908 (bisection?).
Sequence in context: A275313 A288299 A288763 * A143608 A079441 A129418
KEYWORD
nonn
AUTHOR
Clark Kimberling, Dec 30 2011
STATUS
approved