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 A248592 #16 Jan 19 2017 23:30:39 %S A248592 1,1,1,3,3,5,45,315,35,567,14175,51975,467775,868725,2837835, %T A248592 638512875,638512875,1206079875,97692469875,371231385525,441942125625, %U A248592 17717861581875,2143861251406875,16436269594119375,5917057053882975,284473896821296875,1780595872696265625 %N A248592 Denominators of the (simplified) rational numbers n*2^(n - 1)/(n - 1)! . %H A248592 James Burling, <a href="/A248591/a248591_2.pdf">Another Special Rational Sequence</a> %F A248592 a(n) = denom(n * 2^(n - 1) / (n - 1)!). %F A248592 a(n) = denom(g(1, n)) where g(m, n) = m if m = n; 2g(m + 1, n)/m otherwise. %p A248592 A248592 := proc(n) %p A248592 n*2^(n-1)/(n-1)! ; %p A248592 denom(%) ; %p A248592 end proc: %p A248592 seq(A248592(n),n=1..30) ; # _R. J. Mathar_, Oct 10 2014 %o A248592 (PARI) vector(40, n, denominator(n*2^(n - 1)/(n - 1)!)) \\ _Michel Marcus_, Oct 09 2014 %Y A248592 Cf. A248591 (numerators). %Y A248592 Has same start as A241591 but is a different sequence. %K A248592 frac,nonn %O A248592 1,4 %A A248592 _James Burling_, Oct 09 2014 %E A248592 More terms from _Michel Marcus_, Oct 09 2014