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 A074799 #21 Sep 08 2022 08:45:07 %S A074799 1,5,2187,40625,892871875,20841167403,16443713753775,421390226721321, %T A074799 364130196991193221875,9816949116755633084375, %U A074799 8619392462988365485907909,239904481399203205153660455 %N A074799 a(n) = numerator( (4*n+1)*(Product_{i=1..n} (2*i-1)/Product_{i=1..n} 2*i)^5 ). %D A074799 Bruce C. Berndt and Robert Rankin, "Ramanujan : letters and commentary", AMS-LMS, History of mathematics vol. 9, p. 57 %H A074799 Seiichi Manyama, <a href="/A074799/b074799.txt">Table of n, a(n) for n = 0..335</a> %F A074799 a(n) = numerator of (b(n)), where b(n) = (4*n+1)*(Product_{i=1..n} (2*i - 1)/Product_{i=1..n} 2*i)^5 and b(0) = 1. %F A074799 1 + Sum_{k>=1} (-1)^k*b(k) = 2/gamma(3/4)^4 = 0.88694116857811540541... %F A074799 a(n) = numerator( (4*n+1)*( binomial(2*n, n)/4^n )^5 ). - _G. C. Greubel_, Jul 09 2021 %t A074799 Table[Numerator[(4*n+1)*(Binomial[2*n, n]/4^n)^5], {n,0,30}] (* _G. C. Greubel_, Jul 09 2021 *) %o A074799 (PARI) a(n)=numerator((4*n+1)*(prod(i=1,n,2*i-1)/prod(i=1,n,2*i))^5) %o A074799 (Magma) [Numerator((4*n+1)*((n+1)*Catalan(n)/4^n)^5): n in [0..30]]; // _G. C. Greubel_, Jul 09 2021 %o A074799 (Sage) [numerator((4*n+1)*(binomial(2*n, n)/4^n)^5) for n in (0..30)] # _G. C. Greubel_, Jul 09 2021 %Y A074799 Cf. A074800 (denominators). %K A074799 easy,frac,nonn %O A074799 0,2 %A A074799 _Benoit Cloitre_, Sep 08 2002