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 A293474 #15 Oct 11 2017 10:24:05 %S A293474 1,1,3,6,12,9,27,78,81,27,156,564,720,432,81,1110,4320,6930,5400,2025, %T A293474 243,8322,37260,68940,66420,34830,8748,729,70098,347382,722610,824040, %U A293474 541485,200718,35721,2187 %N A293474 Triangle read by rows, coefficients of polynomials in t = log(x) of the n-th derivative of x^(x^3), evaluated at x = 1. T(n, k) with n >= 0 and 0 <= k <= n. %e A293474 Triangle start: %e A293474 0: [ 1] %e A293474 1: [ 1, 3] %e A293474 2: [ 6, 12, 9] %e A293474 3: [ 27, 78, 81, 27] %e A293474 4: [ 156, 564, 720, 432, 81] %e A293474 5: [ 1110, 4320, 6930, 5400, 2025, 243] %e A293474 6: [ 8322, 37260, 68940, 66420, 34830, 8748, 729] %e A293474 7: [70098, 347382, 722610, 824040, 541485, 200718, 35721, 2187] %e A293474 ... %e A293474 For n = 3, the 3rd derivative of x^(x^3) is p(3,x,t) = 27*t^3*x^6*x^(x^3) + 27*t^2*x^6*x^(x^3) + 9*t*x^6*x^(x^3) + x^6*x^(x^3) + 54*t^2*x^3*x^(x^3) + 63*t*x^3*x^(x^3) + 15*x^3*x^(x^3) + 6*t*x^(x^3) + 11*x^(x^3) where log(x) is substituted by t. Evaluated at x = 1: p(3,1,t) = 27 + 78*t + 81*t^2 + 27*t^3 with coefficients [27, 78, 81, 27]. %p A293474 # Function dx in A293472. %p A293474 ListTools:-Flatten([seq(dx(3, n), n=0..8)]); %t A293474 (* Function dx in A293472. *) %t A293474 Table[dx[3, n], {n, 0, 7}] // Flatten %Y A293474 T(n, 0) = A215704, T(n, n) = A000244. %Y A293474 More generally, consider the n-th derivative of x^(x^m). %Y A293474 A293472 (m=1), A293472 (m=2), this seq. (m=3). %K A293474 sign,tabl %O A293474 0,3 %A A293474 _Peter Luschny_, Oct 10 2017