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 A270250 #8 Oct 13 2017 21:39:48 %S A270250 1,2,1,5,5,1,17,24,9,1,77,131,68,14,1,437,833,529,151,20,1,2957,6107, %T A270250 4458,1571,290,27,1,23117,50819,41164,16860,3870,505,35,1,204557, %U A270250 473387,416230,191167,51379,8387,819,44,1,2018957,4880507,4589458,2309303,700776,134716,16541,1258,54,1 %N A270250 Triangle read by rows: coefficients of the polynomial (Sum_{i=0..k} (Product_{j=0..i} (x+j)))/(x*(x+2)). %C A270250 The lines offset is 1, but the columns offset is 0. %H A270250 Lajos Hajdu, Shanta Laishram, Szabolcs Tengely, <a href="http://dx.doi.org/10.4064/aa8271-10-2015">Power values of sums of products of consecutive integers</a>, Acta Arithmetica 172 (2016), 333-349. %e A270250 First rows of this triangle: %e A270250 1; %e A270250 2, 1; %e A270250 5, 5, 1; %e A270250 17, 24, 9, 1; %e A270250 77, 131, 68, 14, 1; %e A270250 ... %o A270250 (PARI) row(n) = Vecrev(sum(i=0, n, prod(j=0, i, x+j))/(x*(x+2))); %Y A270250 Cf. A007489 (values of polynomial when x=2), A014288 (first column). %K A270250 nonn,tabl %O A270250 1,2 %A A270250 _Michel Marcus_, Mar 14 2016