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A005613
Cascade-realizable Boolean functions of n variables.
(Formerly M1982)
4
2, 2, 10, 114, 1842, 37226, 902570, 25530658, 825345250, 30016622298, 1212957186330, 53916514446482, 2614488320210258, 137345270749953610, 7770078330925987210, 470977659902530345986, 30451167044311817097666, 2091878780326890801618362
OFFSET
0,1
REFERENCES
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
LINKS
E. A. Bender and J. T. Butler, Asymptotic approximations for the number of fanout-free functions, IEEE Trans. Computers, 27 (1978), 1180-1183. (Annotated scanned copy)
J. T. Butler, Letter to N. J. A. Sloane, Jun. 1975 and Dec. 1978.
J. T. Butler, On the number of functions realized by cascades and disjunctive networks, IEEE Trans. Computers, C-24 (1975), 681-690. (Annotated scanned copy)
K. L. Kodandapani and S. C. Seth, On combinational networks with restricted fan-out, IEEE Trans. Computers, 27 (1978), 309-318. (Annotated scanned copy)
FORMULA
a(0) = 2, a(1) = 2, a(n) = Sum_{k=1..n-1} ((-1)^(k+1) * binomial(n,k) * (2^(k+1)+1) * a(n-k)) - (-1)^n(2^n+1)a(1). [From Butler] - Sean A. Irvine, Jul 14 2016
CROSSREFS
Sequence in context: A032034 A002250 A304642 * A005616 A005617 A011248
KEYWORD
nonn
EXTENSIONS
More terms from Sean A. Irvine, Jul 14 2016
a(0) added by Sean A. Irvine, Aug 22 2016
STATUS
approved