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a(n) = (F(2n+1) + F(2n-1) + F(n+3) - 2)/2, where F() = Fibonacci numbers A000045.
(Formerly M1414)
1

%I M1414 #27 Apr 13 2022 13:25:17

%S 2,5,12,29,71,177,448,1147,2960,7679,19989,52145,136214,356121,931540,

%T 2437513,6379403,16698113,43710756,114427391,299560472,784236315,

%U 2053119817,5375076769,14072035466,36840908237,96450492828,252510252437

%N a(n) = (F(2n+1) + F(2n-1) + F(n+3) - 2)/2, where F() = Fibonacci numbers A000045.

%D M. D. McIlroy, The number of states of a dynamic storage system, Computer J., 25 (No. 3, 1982), 388-392.

%D N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

%H M. D. McIlroy, <a href="/A005207/a005207.pdf">The number of states of a dynamic storage system</a>, Computer J., 25 (No. 3, 1982), 388-392. (Annotated scanned copy)

%H Simon Plouffe, <a href="https://arxiv.org/abs/0911.4975">Approximations de séries génératrices et quelques conjectures</a>, Dissertation, Université du Québec à Montréal, 1992; arXiv:0911.4975 [math.NT], 2009.

%H Simon Plouffe, <a href="/A000051/a000051_2.pdf">1031 Generating Functions</a>, Appendix to Thesis, Montreal, 1992

%p A005593:=-(-2+5*z-z**2-2*z**3+z**4)/(z-1)/(z**2+z-1)/(z**2-3*z+1); # conjectured by _Simon Plouffe_ in his 1992 dissertation

%t Map[(Fibonacci[2#1+1]+Fibonacci[2#1-1]+Fibonacci[ #1+3]-2)/2&, Range[50]]

%K nonn,easy

%O 1,1

%A _N. J. A. Sloane_

%E More terms from Gabriel Cunningham (gcasey(AT)mit.edu), Oct 25 2004