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 A276997 #17 Sep 09 2018 11:15:33 %S A276997 1,1,1,6,1,1,1,2,2,1,60,1,1,1,1,1,6,2,3,1,1,504,4,4,1,1,1,1,1,24,8,12, %T A276997 2,2,2,1,2160,18,9,3,2,1,3,1,1,1,60,4,6,1,5,1,1,1,1,3168,48,16,6,3,2, %U A276997 2,1,2,1,1,1,288,32,144,12,12,4,2,1,6,2,1 %N A276997 Denominators of coefficients of polynomials arising from applying the complete Bell polynomials to k!B_k(x)/(k*(k-1)) with B_k(x) the Bernoulli polynomials. %C A276997 For formulas and references see A276996. %C A276997 Compare T(n,0) with A220411. %e A276997 Triangle starts: %e A276997 1; %e A276997 1, 1; %e A276997 6, 1, 1; %e A276997 1, 2, 2, 1; %e A276997 60, 1, 1, 1, 1; %e A276997 1, 6, 2, 3, 1, 1; %e A276997 504, 4, 4, 1, 1, 1, 1; %e A276997 1, 24, 8, 12, 2, 2, 2, 1; %e A276997 2160, 18, 9, 3, 2, 1, 3, 1, 1; %p A276997 A276997_row := proc(n) local p; %p A276997 p := (n,x) -> CompleteBellB(n,0,seq((k-2)!*bernoulli(k,x),k=2..n)): %p A276997 seq(denom(coeff(p(n,x),x,k)), k=0..n) end: %p A276997 seq(A276997_row(n), n=0..11); %t A276997 CompleteBellB[n_, zz_] := Sum[BellY[n, k, zz[[1 ;; n-k+1]]], {k, 1, n}]; %t A276997 p[n_, x_] := CompleteBellB[n, Join[{0}, Table[(k-2)! BernoulliB[k, x], {k, 2, n}]]]; %t A276997 row[0] = {1}; row[1] = {1, 1}; row[n_] := CoefficientList[p[n, x], x] // Denominator; %t A276997 Table[row[n], {n, 0, 11}] // Flatten (* _Jean-François Alcover_, Sep 09 2018 *) %Y A276997 Cf. A276996 (numerators), A220411. %K A276997 nonn,frac,tabl %O A276997 0,4 %A A276997 _Peter Luschny_, Oct 01 2016