OFFSET
2,1
COMMENTS
Apparently a duplicate of A028401. - Michel Marcus, May 28 2019
The number of vertices in a Pauli graph of order n is (4^n) - 1. Other invariants and a(n), are given in Table 5, p. 11, of Planat and Saniga.
LINKS
Michel R. P. Planat and Metod Saniga, Pauli graph and finite projective lines/geometries, arXiv:quant-ph/0703154, 2007.
FORMULA
Conjectures from Colin Barker, May 28 2019: (Start)
G.f.: 3*x^2*(5 - 20*x + 16*x^2) / ((1 - x)*(1 - 2*x)*(1 - 4*x)).
a(n) = 7*a(n-1) - 14*a(n-2) + 8*a(n-3) for n>4.
a(n) = (2 + 3*2^n + 4^n) / 2 for n>1.
(End)
PROG
(PARI) a(n) = my(t=2^(n-1), alfa=2^t-1, s=2*alfa); (t+1)*(s*t+alfa)/alfa; \\ Michel Marcus, May 28 2019
CROSSREFS
KEYWORD
nonn
AUTHOR
Jonathan Vos Post, Mar 21 2007
EXTENSIONS
More terms from Michel Marcus, May 28 2019
STATUS
approved