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 A383033 #11 Apr 13 2025 11:41:12 %S A383033 1,1,1,1,2,0,1,3,2,1,1,4,6,5,0,1,5,12,18,6,0,1,6,20,46,42,11,0,1,7,30, %T A383033 95,156,113,18,1,1,8,42,171,420,566,294,35,0,1,9,56,280,930,1930,2028, %U A383033 798,56,0,1,10,72,428,1806,5185,8820,7396,2128,105,0 %N A383033 Square array A(n,k), n >= 1, k >= 1, read by antidiagonals downwards, where A(n,k) is the n-th term of the inverse Weigh transform of j-> k^(j-1). %H A383033 Christian G. Bower, <a href="https://oeis.org/transforms_pari.txt">PARI programs for transforms</a>, 2007. %H A383033 N. J. A. Sloane, <a href="/transforms.txt">Maple programs for transforms</a>, 2001-2020. %F A383033 A(n,k) = (1/n) * (k^n - (k-1)^n + Sum_{d<n and d|n} (-1)^(n/d) * d * A(d,k)). %F A383033 A(n,k) = A383023(n,k) - A383023(n,k-1). %F A383033 Product_{n>=1} (1 + x^n)^A(n,k) = (1 - (k-1)*x)/(1 - k*x). %e A383033 Square array begins: %e A383033 1, 1, 1, 1, 1, 1, 1, ... %e A383033 1, 2, 3, 4, 5, 6, 7, ... %e A383033 0, 2, 6, 12, 20, 30, 42, ... %e A383033 1, 5, 18, 46, 95, 171, 280, ... %e A383033 0, 6, 42, 156, 420, 930, 1806, ... %e A383033 0, 11, 113, 566, 1930, 5185, 11851, ... %e A383033 0, 18, 294, 2028, 8820, 28830, 77658, ... %Y A383033 Columns k=1..3 give A209229, A383034, A383035. %Y A383033 Main diagonal gives A316073. %Y A383033 Cf. A383023. %K A383033 nonn,tabl %O A383033 1,5 %A A383033 _Seiichi Manyama_, Apr 13 2025