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 A330140 #19 Sep 08 2022 08:46:24 %S A330140 1,0,1,0,0,2,0,0,1,4,0,0,1,4,9,0,0,1,5,15,21,0,0,1,6,24,50,51,0,0,1,7, %T A330140 35,98,161,127,0,0,1,8,48,168,378,504,323,0,0,1,9,63,264,750,1386, %U A330140 1554,835,0,0,1,10,80,390,1335,3132,4920,4740,2188 %N A330140 Triangle read by rows: binomial transform of a signed variant of triangle A026300 with alternating signs in each column. %e A330140 The signed variant of triangle A026300 begins: %e A330140 1; %e A330140 -1, 1; %e A330140 1, -2, 2; %e A330140 -1, 3, -5, 4; %e A330140 1, -4, 9, -12, 9; %e A330140 ... %e A330140 The binomial transform of the foregoing is as shown below. %e A330140 Written as a triangle the sequence begins: %e A330140 1; %e A330140 0, 1; %e A330140 0, 0, 2; %e A330140 0, 0, 1, 4; %e A330140 0, 0, 1, 4, 9; %e A330140 0, 0, 1, 5, 15, 21; %e A330140 0, 0, 1, 6, 24, 50, 51; %e A330140 ... %t A330140 F[n_, k_]:= (-1)^(n+k)*Sum[Binomial[n, 2i+n-k]*(Binomial[2i+n-k, i] - Binomial[2i+n-k, i-1]), {i,0,Floor[k/2]}]; T[n_, k_]:= Sum[Binomial[n, j]*F[j, k], {j,k,n}]; Table[T[n, k], {n,0,10}, {k,0,n}]//Flatten (* _G. C. Greubel_, Jan 06 2020 *) %o A330140 (Magma) %o A330140 F:= func< n,k | (-1)^(n+k)*&+[Binomial(n,2*i+n-k)*(Binomial(2*i+n-k,i) - Binomial(2*i+n-k,i-1)): i in [0..Floor(k/2)]] >; %o A330140 T:= func< n,k | &+[Binomial(n,j)*F(j,k): j in [k..n]] >; %o A330140 [T(n,k): k in [0..n], n in [0..10]]; // _G. C. Greubel_, Jan 06 2020 %Y A330140 Right border gives A001006, the Motzkin numbers. %Y A330140 Row sums give A000108, the Catalan numbers. %Y A330140 Cf. A026300, A007318, A330141, A329959. %K A330140 nonn,tabl %O A330140 0,6 %A A330140 _Gary W. Adamson_, Dec 02 2019