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Column 2 of the array in A107735.
1

%I #25 Oct 22 2019 10:17:42

%S 1,3,13,11,141,43,1485,171,15565,683,163021,2731,1707213,10923,

%T 17878221,43691,187223245,174763,1960627405,699051,20531956941,

%U 2796203,215013444813,11184811,2251650026701,44739243,23579585203405,178956971,246928622013645,715827883,2585870100909261,2863311531

%N Column 2 of the array in A107735.

%C The second bisection [3, 11, 43, 171, 683, ...] is A007583. - _Jean-François Alcover_, Oct 22 2019 [noticed by _Paul Curtz_ in a private e-mail].

%D S. Mukai, An Introduction to Invariants and Moduli, Cambridge, 2003; see p. 483.

%H <a href="/index/Rec#order_08">Index entries for linear recurrences with constant coefficients</a>, signature (0,17,0,-80,0,128,0,-64).

%F a(n) = 1 + Sum_{j=1..g} 2^(2j-1) if n = 2g+2, = 1 + 4 Sum_{j=1..g} C(2g+1, 2j) 5^(j-1) if n = 2g+1.

%F From _Chai Wah Wu_, Jun 19 2016: (Start)

%F a(n) = 17*a(n-2) - 80*a(n-4) + 128*a(n-6) - 64*a(n-8) for n > 10.

%F G.f.: x^3*(-64*x^7 + 96*x^5 - 40*x^3 - 4*x^2 + 3*x + 1)/(64*x^8 - 128*x^6 + 80*x^4 - 17*x^2 + 1). (End)

%t LinearRecurrence[{0, 17, 0, -80, 0, 128, 0, -64}, {1, 3, 13, 11, 141, 43, 1485, 171}, 32] (* _Jean-François Alcover_, Oct 22 2019 *)

%Y Cf. A007583, A107735.

%K nonn

%O 3,2

%A _N. J. A. Sloane_, Jun 10 2005

%E More terms from _Emeric Deutsch_, Jun 22 2005