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 A162442 #4 Jul 22 2025 06:54:46 %S A162442 2,16,48,512,1280,2048,14336,262144,589824,2621440,5767168,50331648, %T A162442 109051904,469762048,67108864,34359738368,73014444032,103079215104, %U A162442 652835028992,1099511627776,3848290697216,48378511622144 %N A162442 Denominators of the column sums of the EG1 matrix coefficients. %C A162442 For the definition of the EG1 matrix coefficients see A162440. %C A162442 We define the columns sums by cs(n) = sum(EG1[2*m-1,n], m = 1.. infinity) for n => 2. %F A162442 a(n) = denom(cs(n)) and numer(cs(n)) = A162441(n) with cs(n) = (2^(2-2*n)/(n-1))*((2*n-1)!/((n-1)!^2)). %F A162442 a(n) = denom((1/(n-1))*(2*n-1)*binomial(2*n-2,n-1)/4^(n-1)) %Y A162442 Equals A052469(n-1)/2 for n=>2. %Y A162442 cs(n) = (1/(n-1))*A001803(n-1)/A046161(n-1) for n=>2. %Y A162442 Cf. A162440 and A162441. %K A162442 easy,frac,nonn %O A162442 2,1 %A A162442 _Johannes W. Meijer_, Jul 06 2009