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 A343960 #13 Jun 06 2021 00:51:09
%S A343960 1,1,2,1,5,4,1,9,17,8,1,14,46,49,16,1,20,100,180,129,32,1,27,190,510,
%T A343960 603,321,64,1,35,329,1225,2121,1827,769,128,1,44,532,2618,6202,7700,
%U A343960 5164,1793,256,1,54,816,5124,15876,26628,25392,13878,4097,512
%N A343960 Triangle read by rows: T(n,m) = Sum_{k=1..m} (k/n)*binomial(n,m-k)*binomial(n,m), n >= m >= 1.
%F A343960 T(n,m) = Sum_{k=1..m} (k/n)*binomial(n,m-k)*binomial(n,m).
%F A343960 G.f.: N(x,y)/(1-N(x,y)), where N(x,y) is a g.f. for the Narayana numbers A001263.
%F A343960 T(n, m) = A001263(n, m)*hypergeom([1 - m, 2], [n - m + 2], -1). - _Peter Luschny_, May 06 2021
%e A343960 Triangle begins:
%e A343960 ---------------------------------------------------------------------
%e A343960 n \ m | 1 2 3 4 5 6 7 8 9 10
%e A343960 -------+-------------------------------------------------------------
%e A343960 1 | 1
%e A343960 2 | 1 2
%e A343960 3 | 1 5 4
%e A343960 4 | 1 9 17 8
%e A343960 5 | 1 14 46 49 16
%e A343960 6 | 1 20 100 180 129 32
%e A343960 7 | 1 27 190 510 603 321 64
%e A343960 8 | 1 35 329 1225 2121 1827 769 128
%e A343960 9 | 1 44 532 2618 6202 7700 5164 1793 256
%e A343960 10 | 1 54 816 5124 15876 26628 25392 13878 4097 512
%t A343960 T[n_, m_] := Sum[Binomial[n, m - k] * Binomial[n, m] * k/n, {k, 1, n}]; Table[T[n, m], {n, 1, 10}, {m, 1, n}] // Flatten (* _Amiram Eldar_, May 06 2021 *)
%o A343960 (Maxima)
%o A343960 T(n,m):=sum((k/n)*binomial(n,m-k)*binomial(n,m),k,1,m)
%Y A343960 Cf. A001263.
%K A343960 nonn,tabl
%O A343960 1,3
%A A343960 _Yuriy Shablya_, May 05 2021