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 A004313 #48 Aug 24 2025 04:49:29 %S A004313 1,16,153,1140,7315,42504,230230,1184040,5852925,28048800,131128140, %T A004313 600805296,2707475148,12033222880,52860229080,229911617056, %U A004313 991493848554,4244421484512,18053528883775,76360380541900,321387366339585,1346766106565880,5621728217559090 %N A004313 a(n) = binomial coefficient C(2n, n-7). %D A004313 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 A004313 Seiichi Manyama, <a href="/A004313/b004313.txt">Table of n, a(n) for n = 7..1000</a> %H A004313 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]. %H A004313 Milan Janjic, <a href="https://pmf.unibl.org/wp-content/uploads/2017/10/enumfor.pdf">Two Enumerative Functions</a> %H A004313 Milan Janjic and B. Petkovic, <a href="http://arxiv.org/abs/1301.4550">A Counting Function</a>, arXiv preprint arXiv:1301.4550 [math.CO], 2013. - From _N. J. A. Sloane_, Feb 13 2013 %H A004313 Milan Janjic and B. Petkovic, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL17/Janjic/janjic45.html">A Counting Function Generalizing Binomial Coefficients and Some Other Classes of Integers</a>, J. Int. Seq. 17 (2014), Article 14.3.5. %F A004313 -(n-7)*(n+7)*a(n) + 2*n*(2*n-1)*a(n-1) = 0. - _R. J. Mathar_, Jan 24 2018 %F A004313 E.g.f.: BesselI(7,2*x)*exp(2*x). - _Ilya Gutkovskiy_, Jun 27 2019 %F A004313 From _Amiram Eldar_, Aug 27 2022: (Start) %F A004313 Sum_{n>=7} 1/a(n) = 41*Pi/(9*sqrt(3)) - 24923/3465. %F A004313 Sum_{n>=7} (-1)^(n+1)/a(n) = 51094*log(phi)/(5*sqrt(5)) - 7616722/3465, where phi is the golden ratio (A001622). (End) %t A004313 Table[Binomial[2n,n-7],{n,7,30}] (* _Harvey P. Dale_, Nov 27 2013 *) %o A004313 (Magma) [ Binomial(2*n,n-7): n in [7..150] ]; // _Vincenzo Librandi_, Apr 13 2011 %o A004313 (PARI) a(n)=binomial(2*n,n-7) \\ _Charles R Greathouse IV_, Oct 23 2023 %Y A004313 Diagonal 15 of triangle A100257. %Y A004313 Cf. A001622. %K A004313 nonn,easy,changed %O A004313 7,2 %A A004313 _N. J. A. Sloane_