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%I #39 Dec 06 2024 03:28:38
%S 2,4,16,32,256,512,2048,4096,65536,131072,524288,1048576,8388608,
%T 16777216,67108864,134217728,4294967296,8589934592,34359738368,
%U 68719476736,549755813888,1099511627776,4398046511104,8796093022208
%N a(n) = 2^A101925(n).
%C a(n) is the numerator of 2^(2*n+1)*(n!)^2/(2*n+1)/(2*n)!. The corresponding denominator is A001803. - _Daniel Suteu_, Feb 03 2017
%C a(n) is the numerator of Integral_{x=-oo..oo} sech(x)^(2*n+2) dx. The corresponding denominator is A001803(n). - _Mohammed Yaseen_, Jul 25 2023
%C a(n) is the denominator of (1/Pi) * Integral_{x=0..Pi/2} sin(x)^(2*n) dx. The corresponding numerator is A001790(n). - _Mohammed Yaseen_, Sep 19 2023
%C a(n) = numerator(Pi*binomial(n, -1/2)). - _Peter Luschny_, Dec 05 2024
%H <a href="/index/Di#divseq">Index to divisibility sequences</a>
%p denom((binomial(2n,n)*4^-n)/2); # _Stephen Crowley_, Mar 05 2007
%t Table[Numerator[Beta[1, n + 1, 1/2]], {n, 0, 22}] (* _Gerry Martens_, Nov 13 2016 *)
%Y Bisection of A036069 and of A086117.
%Y Cf. A001803, A001790, A101925.
%K nonn
%O 0,1
%A _Ralf Stephan_, Dec 28 2004
%E More terms from _Joshua Zucker_, May 15 2006