A028402 Number of types of Boolean functions of n variables under a certain group.

6, 20, 72, 272, 1056, 4160, 16512, 65792, 262656, 1049600, 4196352, 16781312, 67117056, 268451840, 1073774592, 4295032832, 17180000256, 68719738880, 274878431232, 1099512676352, 4398048608256, 17592190238720, 70368752566272, 281474993487872, 1125899940397056

Offset

2,1

Links

Vincenzo Librandi, Table of n, a(n) for n = 2..300

I. Strazdins, Universal affine classification of Boolean functions, Acta Applic. Math. 46 (1997), 147-167.

Index entries for sequences related to Boolean functions

Index entries for linear recurrences with constant coefficients, signature (6,-8).

Formula

a(n) = 2^(n-1) * (2^(n-1)+1). - Sean A. Irvine, Jan 07 2020

From Chai Wah Wu, Dec 29 2021: (Start)

a(n) = 6*a(n-1) - 8*a(n-2) for n > 3.

G.f.: x^2*(6 - 16*x)/((2*x - 1)*(4*x - 1)). (End)

Mathematica

Table[2^(n-1) (2^(n-1) + 1), {n, 2, 30}] (* Vincenzo Librandi, Jan 08 2020 *)

Prog

(Magma) [2^(n-1)*(2^(n-1)+1): n in [2..30]]; // Vincenzo Librandi, Jan 08 2020
(PARI) a(n)=2^(n-1)*(2^(n-1)+1) \\ Charles R Greathouse IV, May 26 2026

Crossrefs

Essentially the same as A063376.

Sequence in context: A235367 A189604 A153372 * A092760 A240043 A058494

Adjacent sequences: A028399 A028400 A028401 * A028403 A028404 A028405

Keyword

nonn,easy

Author

N. J. A. Sloane

Extensions

a(6) corrected and more terms from Sean A. Irvine, Jan 07 2020

Status

approved