A005595 States of a dynamic storage system. (Formerly M1069)

1, 2, 4, 7, 13, 23, 46, 88, 186, 395, 880, 1989, 4644, 10934, 26210, 63319, 154377, 378443, 933022, 2308956, 5735371, 14286907, 35683814, 89324137, 224057918, 563033978, 1417210456, 3572641303, 9018885121, 22796905055, 57692673962, 146167385344, 370710166434

Offset

0,2

References

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

Links

Andrew Howroyd, Table of n, a(n) for n = 0..200

C. G. Bower, Transforms

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

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

Index entries for sequences related to bracelets

Formula

Also "DIK" (bracelet, indistinct, unlabeled) transform of 2, 1, 1, 1, ...

G.f.: ((2 - 2*x + x^3)/((1 - x)*(1 - x - x^2)) + Sum_{d>0} phi(d)*log((1-x^d)/(1-3*x^d+x^(2*d)))/d)/2. - Andrew Howroyd, Jun 20 2018

Prog

(PARI) seq(n)={Vec((2 - 2*x + x^3)/((1 - x)*(1 - x - x^2)) + sum(d=1, n, eulerphi(d)/d*log((1-x^d)/(1-3*x^d+x^(2*d)) + O(x*x^n))))/2} \\ Andrew Howroyd, Jun 20 2018

Crossrefs

Sequence in context: A093629 A174566 A018182 * A347025 A296689 A327543

Adjacent sequences: A005592 A005593 A005594 * A005596 A005597 A005598

Keyword

nonn

Author

N. J. A. Sloane

Extensions

Sequence extended by Christian G. Bower

Terms a(30) and beyond from Andrew Howroyd, Jun 20 2018

Status

approved