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 A152059 #42 Feb 22 2024 20:33:16 %S A152059 1,2,13,136,1961,36046,805597,21204548,642451441,22021483546, %T A152059 842527453421,35591363004352,1645373927307673,82625931422081126, %U A152059 4478815087922020861,260648364396903639676,16208855884741850686817 %N A152059 a(n) is the number of ways 2n-1 seats can be occupied by at most n people for n>=1, with a(0)=1. %C A152059 Let A(x) be the e.g.f. of this sequence, and B(x) be the e.g.f. of A082545, then B(x)/A(x) = C(x) where C(x) = 1 + x*C(x)^2 is the Catalan function (A000108). This follows from the fact that this sequence and A082545 form adjacent semi-diagonals of table A088699. - _Paul D. Hanna_, Aug 16 2022 %H A152059 Seiichi Manyama, <a href="/A152059/b152059.txt">Table of n, a(n) for n = 0..366</a> %H A152059 Wikipedia, <a href="https://en.wikipedia.org/wiki/Laguerre_polynomials">Laguerre polynomials</a> %H A152059 <a href="/index/La#Laguerre">Index entries for sequences related to Laguerre polynomials</a> %F A152059 a(n) = Sum_{k=0..n} k! * C(2*n-1,k) * C(n,k). %F A152059 Central terms of triangle A086885 (after initial term). %F A152059 a(n) = n! * [x^n] exp(x/(1 - x))/(1 - x)^n. - _Ilya Gutkovskiy_, Oct 02 2017 %F A152059 a(n) ~ 2^(2*n - 1/2) * n^n / exp(n-1). - _Vaclav Kotesovec_, Oct 02 2017 %F A152059 a(n) = n! * pollaguerre(n, n-1, -1). - _Seiichi Manyama_, May 01 2021 %F A152059 From _Paul D. Hanna_, Aug 16 2022: (Start) %F A152059 E.g.f.: exp( (1-2*x - sqrt(1-4*x))/(2*x) ) / ((sqrt(1-4*x) - (1-4*x))/(2*x)), derived from the e.g.f for A082545 given by _Mark van Hoeij_. %F A152059 E.g.f.: exp(C(x) - 1) / (2 - C(x)), where C(x) = (1 - sqrt(1-4*x))/(2*x) is the Catalan function (A000108). (End) %t A152059 Table[(-1)^n * HypergeometricU[-n, n, -1], {n, 0, 20}] (* _Vaclav Kotesovec_, Oct 02 2017 *) %o A152059 (PARI) a(n)=sum(k=0,n,k!*binomial(2*n-1, k)*binomial(n, k)) %o A152059 (PARI) a(n) = n!*pollaguerre(n, n-1, -1); \\ _Seiichi Manyama_, May 01 2021 %o A152059 (Magma) [Factorial(n)*Evaluate(LaguerrePolynomial(n, n-1), -1): n in [0..40]]; // _G. C. Greubel_, Aug 11 2022 %o A152059 (SageMath) [factorial(n)*gen_laguerre(n, n-1, -1) for n in (0..40)] # _G. C. Greubel_, Aug 11 2022 %Y A152059 Cf. A082545, A086885, A343832, A088699, A000108. %K A152059 nonn %O A152059 0,2 %A A152059 _Paul D. Hanna_, Nov 22 2008