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A074494 Number of 2-input gates used to synthesize parity function in disjunctive normal form (DNF) with n inputs. 1
2, 5, 17, 47, 119, 287, 671, 1535, 3455, 7679, 16895, 36863, 79871, 172031, 368639, 786431, 1671167, 3538943, 7471103, 15728639, 33030143, 69206015, 144703487, 301989887, 629145599, 1308622847, 2717908991, 5637144575, 11676942335 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
FORMULA
a(n) = 3*n * 2^(n-2) - 1 for n>1.
G.f.: x*(2-5*x+8*x^2-6*x^3)/((1-x)*(1-2*x)^2). [Colin Barker, Apr 17 2012]
EXAMPLE
a(7) = 21 * 32 - 1 = 671.
MATHEMATICA
Rest[CoefficientList[Series[x (2-5x+8x^2-6x^3)/((1-x)(1-2x)^2), {x, 0, 30}], x]] (* Harvey P. Dale, Feb 18 2013 *)
CROSSREFS
Sequence in context: A215580 A275210 A219554 * A051438 A368756 A148401
KEYWORD
easy,nonn
AUTHOR
Nikolay S. Maltchev (nikolay(AT)maltchev.com), Sep 25 2002
STATUS
approved

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Last modified June 18 21:09 EDT 2024. Contains 373487 sequences. (Running on oeis4.)