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 A051381 #20 Jul 02 2025 16:01:58
%S A051381 1,3,19,471,162631,12884412819,64563604212887416603,
%T A051381 1361129467683753853595244012815395920687,
%U A051381 521064401567922879406069432539095585333589848390805645835993148352662477920015
%N A051381 Number of Boolean functions of n variables from Post class F(5,inf).
%H A051381 G. C. Greubel, <a href="/A051381/b051381.txt">Table of n, a(n) for n = 1..12</a>
%H A051381 V. Jovovic, G. Kilibarda, <a href="http://dx.doi.org/10.4213/dm398">On the number of Boolean functions in the Post classes F^{mu}_8</a>, Diskretnaya Matematika, 11 (1999), no. 4, 127-138.
%H A051381 V. Jovovic, G. Kilibarda, <a href="http://dx.doi.org/10.1515/dma.1999.9.6.593">On the number of Boolean functions in the Post classes F^{mu}_8</a>, (English translation), Discrete Mathematics and Applications, 9, (1999), no. 6.
%H A051381 S. Spasovski and A. M. Bogdanova, <a href="http://ciit.finki.ukim.mk/data/files/spasovski/Optimization%20of%20the%20Polynomial%20Greedy%20Solution%20for%20the%20Set%20Covering%20Problem.pdf">Optimization of the Polynomial Greedy Solution for the Set Covering Problem</a>, 2013, 10th Conference for Informatics and Information Technology (CIIT 2013).
%H A051381 <a href="/index/Bo#Boolean">Index entries for sequences related to Boolean functions</a>
%F A051381 a(n) = Sum_{j=1..n} (-1)^(j+1)*C(n, j)*2^(2^(n-j)-1).
%t A051381 Table[Sum[(-1)^(j + 1)*Binomial[n, j]*2^(2^(n - j) - 1) , {j, 1, n}], {n, 1, 5}] (* _G. C. Greubel_, Oct 08 2017 *)
%Y A051381 Cf. A036239, A036240. Equals A005530(n)/2.
%K A051381 easy,nonn
%O A051381 1,2
%A A051381 _Vladeta Jovovic_, Goran Kilibarda
%E A051381 More terms from _James Sellers_