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 A162441 #5 Jul 22 2025 06:54:39 %S A162441 3,15,35,315,693,1001,6435,109395,230945,969969,2028117,16900975, %T A162441 35102025,145422675,20036013,9917826435,20419054425,27981667175, %U A162441 172308161025,282585384081,964378691705,11835556670925,24185702762325 %N A162441 Numerators of the column sums of the EG1 matrix coefficients. %C A162441 For the definition of the EG1 matrix coefficients see A162440. %C A162441 We define the columns sums by cs(n) = sum(EG1[2*m-1,n], m = 1.. infinity) for n => 2. %C A162441 The row sums of the EG1 matrix follow the same pattern as those of its even counterpart the EG2 matrix, see A161739 and the formulas. %F A162441 a(n) = numer(cs(n)) and denom(cs(n)) = A162442(n) with cs(n) = (2^(2-2*n)/(n-1))*((2*n-1)!/((n-1)!^2)). %F A162441 cs(n) = 2*EG1[ -1,n]/(n-1) with EG1[ -1,n] = 2^(1-2*n)*(2*n-1)!/((n-1)!^2). %F A162441 cs(n) = (1/(n-1))*A001803(n-1)/A046161(n-1) for n=>2. %F A162441 rs(2*m-1,p=0) = sum((n^p)*EG1(2*m-1,n), n = 1..infinity) = 2*zeta(2*m-2) for m =>2. %Y A162441 Equals (2*n-1)*A052468(n-1) %Y A162441 Cf. A162440 and A162442 [denom(cs(n))]. %Y A162441 Cf. A161739 (RSEG2 triangle), A001803 and A046161. %K A162441 easy,frac,nonn %O A162441 2,1 %A A162441 _Johannes W. Meijer_, Jul 06 2009