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 A289192 #52 Feb 16 2025 08:33:48 %S A289192 1,1,1,1,2,2,1,3,7,6,1,4,14,34,24,1,5,23,86,209,120,1,6,34,168,648, %T A289192 1546,720,1,7,47,286,1473,5752,13327,5040,1,8,62,446,2840,14988,58576, %U A289192 130922,40320,1,9,79,654,4929,32344,173007,671568,1441729,362880 %N A289192 A(n,k) = n! * Laguerre(n,-k); square array A(n,k), n>=0, k>=0, read by antidiagonals. %H A289192 Alois P. Heinz, <a href="/A289192/b289192.txt">Antidiagonals n = 0..140, flattened</a> %H A289192 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/LaguerrePolynomial.html">Laguerre Polynomial</a> %H A289192 Wikipedia, <a href="https://en.wikipedia.org/wiki/Laguerre_polynomials">Laguerre polynomials</a> %H A289192 <a href="/index/La#Laguerre">Index entries for sequences related to Laguerre polynomials</a> %F A289192 A(n,k) = n! * Sum_{i=0..n} k^i/i! * binomial(n,i). %F A289192 E.g.f. of column k: exp(k*x/(1-x))/(1-x). %F A289192 A(n, k) = (-1)^n*KummerU(-n, 1, -k). - _Peter Luschny_, Feb 12 2020 %F A289192 A(n, k) = (2*n+k-1)*A(n-1, k) - (n-1)^2*A(n-2, k) for n > 1. - _Seiichi Manyama_, Feb 03 2021 %e A289192 Square array A(n,k) begins: %e A289192 : 1, 1, 1, 1, 1, 1, ... %e A289192 : 1, 2, 3, 4, 5, 6, ... %e A289192 : 2, 7, 14, 23, 34, 47, ... %e A289192 : 6, 34, 86, 168, 286, 446, ... %e A289192 : 24, 209, 648, 1473, 2840, 4929, ... %e A289192 : 120, 1546, 5752, 14988, 32344, 61870, ... %p A289192 A:= (n,k)-> n! * add(binomial(n, i)*k^i/i!, i=0..n): %p A289192 seq(seq(A(n, d-n), n=0..d), d=0..12); %t A289192 A[n_, k_] := n! * LaguerreL[n, -k]; %t A289192 Table[A[n - k, k], {n, 0, 9}, {k, n, 0, -1}] // Flatten (* _Jean-François Alcover_, May 05 2019 *) %o A289192 (Python) %o A289192 from sympy import binomial, factorial as f %o A289192 def A(n, k): return f(n)*sum(binomial(n, i)*k**i/f(i) for i in range(n + 1)) %o A289192 for n in range(13): print([A(k, n - k) for k in range(n + 1)]) # _Indranil Ghosh_, Jun 28 2017 %o A289192 (PARI) {T(n, k) = if(n<2, k*n+1, (2*n+k-1)*T(n-1, k)-(n-1)^2*T(n-2, k))} \\ _Seiichi Manyama_, Feb 03 2021 %o A289192 (PARI) T(n, k) = n!*pollaguerre(n, 0, -k); \\ _Michel Marcus_, Feb 05 2021 %Y A289192 Columns k=0-10 give: A000142, A002720, A087912, A277382, A289147, A289211, A289212, A289213, A289214, A289215, A289216. %Y A289192 Rows n=0-2 give: A000012, A000027(k+1), A008865(k+2). %Y A289192 Main diagonal gives A277373. %Y A289192 Cf. A253286, A341014. %K A289192 nonn,tabl %O A289192 0,5 %A A289192 _Alois P. Heinz_, Jun 28 2017