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 A290318 #9 Dec 16 2017 15:29:58 %S A290318 1,2,1,6,1,1,4,1,2,1,30,1,1,1,1,4,1,1,3,2,1,84,1,1,1,2,1,1,24,1,1,3,4, %T A290318 1,2,1,90,1,1,1,1,1,3,1,1,20,1,1,1,1,5,1,1,2,1,132,1,1,1,1,1,1,1,2,1,1 %N A290318 Triangle read by rows. Row n gives the denominators of the coefficients of the Bernoulli polynomials of the second kind (in rising powers). %C A290318 The numerators appear in A290317, where more information is found. %C A290318 The LCM of row n seems to be A002790(n). %C A290318 The first column is given by A006233. %e A290318 The triangle T(n, k) begins: %e A290318 n\k 0 1 2 3 4 5 6 7 8 9 10 ... %e A290318 0: 1 %e A290318 1: 2 1 %e A290318 2: 6 1 1 %e A290318 3: 4 1 2 1 %e A290318 4: 30 1 1 1 1 %e A290318 5: 4 1 1 3 2 1 %e A290318 6: 84 1 1 1 2 1 1 %e A290318 7: 24 1 1 3 4 1 2 1 %e A290318 8: 90 1 1 1 1 1 3 1 1 %e A290318 9: 20 1 1 1 1 5 1 1 2 1 %e A290318 10: 132 1 1 1 1 1 1 1 2 1 1 %e A290318 ... %e A290318 For the first rows of the rational triangle r(n, m) see A290317. %Y A290318 Cf. A002790, A006233, A290317 (numerators). %K A290318 nonn,easy,frac,tabl %O A290318 0,2 %A A290318 _Wolfdieter Lang_, Aug 06 2017 %E A290318 Definition corrected by _Eric M. Schmidt_, Dec 16 2017