

A005595


States of a dynamic storage system.
(Formerly M1069)


1



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
(list;
graph;
refs;
listen;
history;
text;
internal format)



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), 388392.
M. D. McIlroy, The number of states of a dynamic storage system, Computer J., 25 (No. 3, 1982), 388392. (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((1x^d)/(13*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((1x^d)/(13*x^d+x^(2*d)) + O(x*x^n))))/2} \\ Andrew Howroyd, Jun 20 2018


CROSSREFS

Sequence in context: A093629 A174566 A018182 * A296689 A327543 A096236
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



