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 A259326 #7 Aug 16 2015 17:28:48 %S A259326 1,2,26,141907500,17844701940490373256193966080, %T A259326 59757436204078657410908164193971177467473348779378572774972093904092502425600000 %N A259326 Ceiling of ((2^n)!+(2^n-1)^2*(2^(n-1))!*2^(2^(n-1)))/(4^n*(n!)^2). %H A259326 C. S. Lorens, <a href="http://dx.doi.org/10.1109/PGEC.1964.263724">Invertible Boolean functions</a>, IEEE Trans. Electron. Computers, EC-13 (1964), 529-541. %H A259326 C. S. Lorens, <a href="/A000722/a000722.pdf">Invertible Boolean functions</a>, IEEE Trans. Electron. Computers, EC-13 (1964), 529-541. [Annotated scan of page 530 only] %p A259326 # Maple code for A259326, A259327, A259328, A259329, A259330, A259331: %p A259326 f:=n->((2^n)!+(2^n-1)^2*(2^(n-1))!*2^(2^(n-1)))/(4^n*(n!)^2); %p A259326 f:=n->((2^n)!)/(4^n*(n!)^2); %p A259326 f:=n->((2^n)!)/(2^(n*(n-1))*mul((2^i-1)^2,i=1..n)); %p A259326 f:=n->((2^n)!)/(4^(n^2)); %p A259326 f:=n->((2^n)!)/(2^(n*(n+1))*mul((2^i-1)^2,i=1..n)); %p A259326 f:=n->((2^n)!)/(4^n*2^(2*n^2)); %p A259326 [seq(ceil(f(n)),n=1..6)]; %Y A259326 Cf. A259327, A259328, A259329, A259330, A259331. %K A259326 nonn %O A259326 1,2 %A A259326 _N. J. A. Sloane_, Jun 24 2015