A005593 a(n) = (F(2n+1) + F(2n-1) + F(n+3) - 2)/2, where F() = Fibonacci numbers A000045. (Formerly M1414)

2, 5, 12, 29, 71, 177, 448, 1147, 2960, 7679, 19989, 52145, 136214, 356121, 931540, 2437513, 6379403, 16698113, 43710756, 114427391, 299560472, 784236315, 2053119817, 5375076769, 14072035466, 36840908237, 96450492828, 252510252437

Offset

1,1

References

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

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

Links

Table of n, a(n) for n=1..28.

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

Simon Plouffe, Approximations de séries génératrices et quelques conjectures, Dissertation, Université du Québec à Montréal, 1992; arXiv:0911.4975 [math.NT], 2009.

Simon Plouffe, 1031 Generating Functions, Appendix to Thesis, Montreal, 1992

Maple

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

Mathematica

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

Crossrefs

Sequence in context: A054196 A131710 A227237 * A122745 A166292 A010374

Adjacent sequences: A005590 A005591 A005592 * A005594 A005595 A005596

Keyword

nonn,easy

Author

N. J. A. Sloane

Extensions

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

Status

approved