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A001320
Number of self-complementary Boolean functions of n variables: see Comments for precise definition.
(Formerly M2982 N1204)
1
1, 3, 14, 240, 63488, 4227858432, 18302628885633695744, 338953138925153547590470800371487866880, 115565932813024562229384322928592814283244066726840484812818018414147674308608
OFFSET
1,2
COMMENTS
Number of self-complementary equivalence classes under the group C_{2^n} of all 2^n complementations of variables. - R. J. Mathar, Apr 14 2010
The next term (a(10)) has 155 digits. - Harvey P. Dale, Jul 27 2011
REFERENCES
M. A. Harrison, The number of equivalence classes of Boolean functions under groups containing negation, IEEE Trans. Electron. Comput. 12 (1963), 559-561.
N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
FORMULA
a(n) = 2^(2^(n-1)) * (2^n-1) / 2^n. - Zerinvary Lajos, Oct 24 2006, corrected by R. J. Mathar, Apr 14 2010
a(n) = A016031(n)*A000079(n-1). - R. J. Mathar, Apr 14 2010
MAPLE
a:=n->sum(((fermat(n)-1))/2^(j+1), j=0..n): seq(a(n), n=0..8); # Zerinvary Lajos, Oct 24 2006
MATHEMATICA
Table[2^(2^(n-1))(2^n-1)/2^n, {n, 10}] (* Harvey P. Dale, Jul 27 2011 *)
CROSSREFS
Cf. A000610.
Sequence in context: A288563 A081383 A351139 * A133028 A144985 A168590
KEYWORD
nonn,easy,nice
EXTENSIONS
More terms from Vladeta Jovovic, Feb 23 2000
STATUS
approved