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 A115903 #20 Jan 27 2024 10:29:58 %S A115903 1,18,270,3780,51030,673596,8756748,112586760,1435481190,18182761740, %T A115903 229102797924,2874198737592,35927484219900,447711726432600, %U A115903 5564417171376600,68998772925069840,853859814947739270,10547680067001485100,130088054159684982900,1602137088071909789400 %N A115903 Expansion of (1-12*x)^(-3/2). %H A115903 Vincenzo Librandi, <a href="/A115903/b115903.txt">Table of n, a(n) for n = 0..200</a> %F A115903 G.f.: 1/((1-12*x)*sqrt(1-12*x)). %F A115903 a(n) = Jacobi_P(n,1/2,1/2,1)*12^n. %F A115903 a(n) = 3^n*(2*n+1)*binomial(2*n,n) = 3^n*A002457(n). %F A115903 a(n) = (2*n+1)*A098658(n). %F A115903 D-finite with recurrence: n*a(n) - 6*(2*n+1)*a(n-1) = 0. - _R. J. Mathar_, Nov 07 2012 %F A115903 From _Amiram Eldar_, Jan 27 2024: (Start) %F A115903 Sum_{n>=0} 1/a(n) = 12*arcsin(1/sqrt(12))/sqrt(11). %F A115903 Sum_{n>=0} (-1)^n/a(n) = 12*arcsinh(1/sqrt(12))/sqrt(13). (End) %t A115903 CoefficientList[Series[(1-12x)^(-3/2),{x,0,20}],x] (* _Harvey P. Dale_, Oct 26 2016 *) %o A115903 (Magma) [(3^n*Factorial(2*n)/Factorial(n)^2)*(2*n+1): n in [0..20]]; // _Vincenzo Librandi_, Jul 05 2011 %Y A115903 Cf. A002457, A098658. %K A115903 easy,nonn %O A115903 0,2 %A A115903 _Paul Barry_, Feb 02 2006