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 A160473 #10 Sep 08 2022 08:45:45 %S A160473 3,30,315,11340,311850,12162150,638512875,86837751000,7424627710500, %T A160473 779585909602500,98617617564716250,14792642634707437500, %U A160473 2596108782391155281250,527010082825404522093750,122529844256906551386796875,64695757767646659132228750000 %N A160473 The p(n) sequence that is associated with the Eta triangle A160464. %F A160473 a(n) = 2^(-(2*(n-1)-1-floor(log(n-1)/log(2))))*(2*n-1)! for n = 2, 3, 4, ... . %o A160473 (PARI) vector(20, n, n++; 2^(-(2*(n-1)-1-floor(log(n-1)/log(2))))*(2*n-1)!) \\ _Michel Marcus_, Jul 06 2015 %o A160473 (Magma) [2^(-(2*(n-1)-1-Floor(Log(n-1)/Log(2))))*Factorial(2*n-1) : n in [2..30]]; // _Vincenzo Librandi_, Jul 06 2015 %Y A160473 A160464 is the Eta triangle. %Y A160473 Equals 3*(n-2)!*A000457(n-2)/A054243(n-1) %Y A160473 Equals 2^(-A049039(n-1))*(2*n-1)! %Y A160473 Cf. The pg(n) sequence A162440. - _Johannes W. Meijer_, Jul 06 2009 %K A160473 easy,nonn %O A160473 2,1 %A A160473 _Johannes W. Meijer_, May 24 2009