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 A278072 #12 Mar 27 2020 10:55:38 %S A278072 1,-1,1,1,1,1,-1,4,3,1,1,10,11,5,1,-1,32,37,22,7,1,1,100,128,88,37,9, %T A278072 1,-1,329,444,341,171,56,11,1,1,1101,1558,1297,739,294,79,13,1,-1, %U A278072 3761,5514,4891,3069,1406,465,106,15,1,1,13035,19680,18365,12435,6346,2442,692,137,17,1 %N A278072 Riordan array(1/(1+x), (1-sqrt(1-4*x))/(2*x)). %e A278072 [ 1] %e A278072 [ -1, 1] %e A278072 [ 1, 1, 1] %e A278072 [ -1, 4, 3, 1] %e A278072 [ 1, 10, 11, 5, 1] %e A278072 [ -1, 32, 37, 22, 7, 1] %e A278072 [ 1, 100, 128, 88, 37, 9, 1] %e A278072 [ -1, 329, 444, 341, 171, 56, 11, 1] %t A278072 (* The function RiordanArray is defined in A256893. *) %t A278072 RiordanArray[1/(1+#)&, (1-Sqrt[1-4#])/(2#)&, 11] // Flatten (* _Jean-François Alcover_, Jul 16 2019 *) %o A278072 (Sage) # uses[riordan_array from A256893] %o A278072 riordan_array(1/(1+x), (1-sqrt(1-4*x))/(2*x), 8) %Y A278072 Cf. A033297, A084849. %K A278072 sign,tabl %O A278072 0,8 %A A278072 _Peter Luschny_, Nov 22 2016