A203230 (n-1)-st elementary symmetric function of the first n terms of A010684.

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

Links

Table of n, a(n) for n=1..32.

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

Adjacent sequences: A203227 A203228 A203229 * A203231 A203232 A203233

Keyword

nonn

Author

Clark Kimberling, Dec 30 2011

Status

approved