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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 (list; graph; refs; listen; history; text; internal format)
 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). LINKS M. A. Harrison, The number of equivalence classes of Boolean functions under groups containing negation, IEEE Trans. Electron. Comput. 12 (1963), 559-561. [Annotated scanned copy] 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: A288555 A288563 A081383 * A133028 A144985 A168590 Adjacent sequences:  A001317 A001318 A001319 * A001321 A001322 A001323 KEYWORD nonn,easy,nice AUTHOR EXTENSIONS More terms from Vladeta Jovovic, Feb 23 2000 STATUS approved

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