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 A004343 #22 Jul 22 2024 15:20:46
%S A004343 1,10,105,1140,12650,142506,1623160,18643560,215553195,2505433700,
%T A004343 29248649430,342700125300,4027810484880,47465835030320,
%U A004343 560658857389200,6635869816740560,78682166288559225,934433788613079150
%N A004343 Binomial coefficient C(5n,n-1).
%D A004343 M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards Applied Math. Series 55, 1964 (and various reprintings), p. 828.
%H A004343 Seiichi Manyama, <a href="/A004343/b004343.txt">Table of n, a(n) for n = 1..922</a>
%H A004343 M. Abramowitz and I. A. Stegun, eds., <a href="http://www.convertit.com/Go/ConvertIt/Reference/AMS55.ASP">Handbook of Mathematical Functions</a>, National Bureau of Standards, Applied Math. Series 55, Tenth Printing, 1972 [alternative scanned copy].
%F A004343 From _Peter Bala_, Jul 21 2024: (Start)
%F A004343 a(n) = Sum_{k = 0..n-1} binomial(4*n+k, k).
%F A004343 a(n) = 5*(5*n - 1)*(5*n - 2)*(5*n - 3)*(5*n - 4)/((4*n - 4)*(4*n - 2)*(4*n - 1)*(4*n + 1)) * a(n-1) with a(1) = 1. (End)
%Y A004343 Cf. A001791, A004319, A004331, A004356, A004369, A004382.
%K A004343 nonn,easy
%O A004343 1,2
%A A004343 _N. J. A. Sloane_