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 A382101 #19 Mar 16 2025 12:42:09 %S A382101 1,1,1,1,1,1,1,1,3,1,1,1,5,13,1,1,1,7,43,73,1,1,1,9,91,529,501,1,1,1, %T A382101 11,157,1753,8501,4051,1,1,1,13,241,4129,45001,169021,37633,1,1,1,15, %U A382101 343,8041,146001,1447471,4010455,394353,1,1,1,17,463,13873,362501,6502681,56041987,110676833,4596553,1 %N A382101 Square array A(n,k), n >= 0, k >= 0, read by antidiagonals downwards, where column k is the expansion of e.g.f. exp(B_k(x) - 1), where B_k(x) = 1 + x*B_k(x)^k. %H A382101 Wikipedia, <a href="https://en.wikipedia.org/wiki/Laguerre_polynomials">Laguerre polynomials</a> %H A382101 <a href="/index/La#Laguerre">Index entries for sequences related to Laguerre polynomials</a> %F A382101 A(n,k) = (n-1)! * Sum_{j=0..n-1} binomial(k*n,j)/(n-j-1)! for n > 0. %F A382101 A(n,k) = (n-1)! * LaguerreL(n-1, (k-1)*n+1, -1) for n > 0. %F A382101 E.g.f. of column k: exp( Series_Reversion( x/(1+x)^k ) ). %e A382101 Square array begins: %e A382101 1, 1, 1, 1, 1, 1, ... %e A382101 1, 1, 1, 1, 1, 1, ... %e A382101 1, 3, 5, 7, 9, 11, ... %e A382101 1, 13, 43, 91, 157, 241, ... %e A382101 1, 73, 529, 1753, 4129, 8041, ... %e A382101 1, 501, 8501, 45001, 146001, 362501, ... %o A382101 (PARI) a(n, k) = if(n==0, 1, (n-1)!*pollaguerre(n-1, (k-1)*n+1, -1)); %Y A382101 Columns k=0..4 give A000012, A000262, A251568, A380512, A380516. %Y A382101 Cf. A355262, A382100. %K A382101 nonn,tabl %O A382101 0,9 %A A382101 _Seiichi Manyama_, Mar 15 2025