A271480 Dimension of n-qubit subspace H^{MPS}_{2,n} for bond dimension 2.

1, 2, 4, 8, 16, 30, 53, 88, 139, 210, 306, 432, 594, 798, 1051, 1360

Offset

0,2

Links

Table of n, a(n) for n=0..15.

M. Navascues, T. Vertesi, The Structure of Matrix Product States, arXiv preprint arXiv:1509.04507 [quant-ph], 2015.

Formula

Conjectures from Colin Barker, Apr 26 2016: (Start)

a(n) = (93+3*(-1)^n+88*n+4*n^2+8*n^3+2*n^4)/96.

a(n) = (n^4+4*n^3+2*n^2+44*n+48)/48 for n even.

a(n) = (n^4+4*n^3+2*n^2+44*n+45)/48 for n odd.

a(n) = 4*a(n-1)-5*a(n-2)+5*a(n-4)-4*a(n-5)+a(n-6) for n>5.

G.f.: (1-2*x+x^2+2*x^3-x^4) / ((1-x)^5*(1+x)).

(End)

Crossrefs

Sequence in context: A098904 A248846 A046127 * A226454 A347775 A075529

Adjacent sequences: A271477 A271478 A271479 * A271481 A271482 A271483

Keyword

nonn,more

Author

N. J. A. Sloane, Apr 12 2016

Status

approved