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 A356602 #15 Dec 10 2023 11:10:43 %S A356602 1,1,0,-1,1,0,1,-1,1,0,-1,11,-11,1,0,1,-13,11,-13,1,0,-1,19,-151,302, %T A356602 -19,1,0,1,-5,1191,-302,397,-15,1,0,-1,247,-477,15619,-15619,477,-247, %U A356602 1,0,1,-251,1826,-44117,15619,-44117,1826,-251,1,0 %N A356602 Triangle read by rows. T(n, k) = numerator(Integral_{z=0..1} Eulerian(n, k)*z^(k + 1)*(z - 1)^(n - k - 1) dz), where Eulerian(n, k) = A173018(n, k) for n >= 1, and T(0, 0) = 1. %F A356602 R(n, k) = (-1)^(k - n + 1)*Eulerian(n, k)*Gamma(k + 2)*Gamma(n - k)/Gamma(n + 2) for 0 <= k < n, and T(n, n) = 0^n. %F A356602 Bernoulli(n) = Sum_{k=0..n} R(n, k), where Bernoulli(1) = 1/2. %F A356602 T(n, k) = numerator(R(n, k)). %e A356602 Triangle T(n, k) starts: %e A356602 [0] 1; %e A356602 [1] 1, 0; %e A356602 [2] -1, 1, 0; %e A356602 [3] 1, -1, 1, 0; %e A356602 [4] -1, 11, -11, 1, 0; %e A356602 [5] 1, -13, 11, -13, 1, 0; %e A356602 [6] -1, 19, -151, 302, -19, 1, 0; %e A356602 [7] 1, -5, 1191, -302, 397, -15, 1, 0; %e A356602 [8] -1, 247, -477, 15619, -15619, 477, -247, 1, 0; %e A356602 [9] 1, -251, 1826, -44117, 15619, -44117, 1826, -251, 1, 0; %e A356602 The Bernoulli numbers (with B(1) = 1/2) are the row sums of the fractions. %e A356602 [0] 1 = 1; %e A356602 [1] + 1/2 = 1/2; %e A356602 [2] - 1/6 + 1/3 = 1/6; %e A356602 [3] + 1/12 - 1/3 + 1/4 = 0; %e A356602 [4] - 1/20 + 11/30 - 11/20 + 1/5 = -1/30; %e A356602 [5] + 1/30 - 13/30 + 11/10 - 13/15 + 1/6 = 0; %e A356602 [6] - 1/42 + 19/35 - 151/70 + 302/105 - 19/14 + 1/7 = 1/42; %p A356602 E1 := proc(n, k) combinat:-eulerian1(n, k) end: %p A356602 Trow := proc(n, z) if n = 0 then return 1 fi; %p A356602 seq(numer(int(E1(n, k)*z^(k + 1)*(z - 1)^(n - k - 1), z=0..1)), k=0..n) end: %p A356602 for n from 0 to 9 do Trow(n, z) od; %t A356602 Unprotect[Power]; Power[0, 0] = 1; %t A356602 E1[n_, k_] /; n == k = 0^k; E1[n_, k_] /; k < 0 || k > n = 0; %t A356602 E1[n_, k_] := E1[n, k] = (k + 1)*E1[n - 1, k] + (n - k)*E1[n - 1, k - 1]; %t A356602 T[n_, k_] /; n == k = 0^k; %t A356602 T[n_, k_] := (-1)^(k - n + 1)*E1[n, k]*Gamma[k + 2]*Gamma[n - k]/Gamma[n + 2]; %t A356602 Table[Numerator[T[n, k]], {n, 0, 8}, {k, 0, n}] // TableForm %Y A356602 Cf. A356601 (denominator), A173018, A278075, A356545, A356547. %K A356602 sign,tabl,frac %O A356602 0,12 %A A356602 _Peter Luschny_, Aug 15 2022