This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A028402 #25 Jul 08 2025 18:33:36
%S A028402 6,20,72,272,1056,4160,16512,65792,262656,1049600,4196352,16781312,
%T A028402 67117056,268451840,1073774592,4295032832,17180000256,68719738880,
%U A028402 274878431232,1099512676352,4398048608256,17592190238720,70368752566272,281474993487872,1125899940397056
%N A028402 Number of types of Boolean functions of n variables under a certain group.
%H A028402 Vincenzo Librandi, <a href="/A028402/b028402.txt">Table of n, a(n) for n = 2..300</a>
%H A028402 I. Strazdins, <a href="https://doi.org/10.1023/A:1005769927571">Universal affine classification of Boolean functions</a>, Acta Applic. Math. 46 (1997), 147-167.
%H A028402 <a href="/index/Bo#Boolean">Index entries for sequences related to Boolean functions</a>
%H A028402 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (6,-8).
%F A028402 a(n) = 2^(n-1) * (2^(n-1)+1). - _Sean A. Irvine_, Jan 07 2020
%F A028402 From _Chai Wah Wu_, Dec 29 2021: (Start)
%F A028402 a(n) = 6*a(n-1) - 8*a(n-2) for n > 3.
%F A028402 G.f.: x^2*(6 - 16*x)/((2*x - 1)*(4*x - 1)). (End)
%t A028402 Table[2^(n-1) (2^(n-1) + 1), {n, 2, 30}] (* _Vincenzo Librandi_, Jan 08 2020 *)
%o A028402 (Magma) [2^(n-1)*(2^(n-1)+1): n in [2..30]]; // _Vincenzo Librandi_, Jan 08 2020
%Y A028402 Essentially the same as A063376.
%K A028402 nonn
%O A028402 2,1
%A A028402 _N. J. A. Sloane_
%E A028402 a(6) corrected and more terms from _Sean A. Irvine_, Jan 07 2020