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 A375597 #6 Aug 21 2024 05:34:54 %S A375597 1,1,1,2,4,10,6,14,34,82,24,60,152,388,1000,120,312,816,2144,5656, %T A375597 14968,720,1920,5136,13776,37040,99808,269488,5040,13680,37200,101328, %U A375597 276432,755216,2066032,5659120,40320,110880,305280,841440,2321664,6412128,17725952,49045792,135819136 %N A375597 Triangle read by rows: T(n, k) = n! * 3^k * hypergeom([-k], [-n], -2/3). %F A375597 T(n, k) = (-2)^k*Sum_{j=0..k} (-3/2)^(k - j)*binomial(k, k - j)*(n - j)!. %e A375597 Triangle starts: %e A375597 [0] 1; %e A375597 [1] 1, 1; %e A375597 [2] 2, 4, 10; %e A375597 [3] 6, 14, 34, 82; %e A375597 [4] 24, 60, 152, 388, 1000; %e A375597 [5] 120, 312, 816, 2144, 5656, 14968; %e A375597 [6] 720, 1920, 5136, 13776, 37040, 99808, 269488; %e A375597 [7] 5040, 13680, 37200, 101328, 276432, 755216, 2066032, 5659120; %e A375597 ... %t A375597 T[n_, k_] := (-2)^k*Sum[(-3/2)^(k - j)*Binomial[k, k - j]*(n - j)!, {j, 0, k}]; %t A375597 Table[T[n, k], {n, 0, 8}, {k, 0, n}] // Flatten %Y A375597 Cf. A375600, A000142. %Y A375597 Cf. A374427, A374428, A375446, A375447. %K A375597 nonn,tabl %O A375597 0,4 %A A375597 _Detlef Meya_, Aug 20 2024