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 A298309 #13 Jan 22 2018 21:26:01 %S A298309 0,1,1,2,4,2,3,11,13,5,4,25,51,43,13,5,49,149,203,130,32,6,86,364,716, %T A298309 734,382,80,7,139,787,2099,3061,2521,1105,201,8,211,1553,5385,10455, %U A298309 12093,8311,3143,505,9,305,2851,12473,30918,47064,45075,26581,8843,1273 %N A298309 Triangle read by rows: T(n,m) = Sum_{i=0..n+1} C(n-i+1,i-1)*C(n-i+1,i)*C(n-i+1,m-i+1). %F A298309 G.f.: ((1-(1-x*y)*(x*y+x))/sqrt((1-(x*y+1)*(x*y+x))^2-4*x*y*(x*y+x)^2)-1)/(2*x*y). %e A298309 Triangle begins %e A298309 0; %e A298309 1, 1; %e A298309 2, 4, 2; %e A298309 3, 11, 13, 5; %e A298309 4, 25, 51, 43, 13; %e A298309 5, 49, 149, 203, 130, 32; %e A298309 6, 86, 364, 716, 734, 382, 80; %e A298309 7, 139, 787, 2099, 3061, 2521, 1105, 201; %o A298309 (Maxima) %o A298309 T(n,m):=sum(binomial(n-i+1,i-1)*binomial(n-i+1,i)*binomial(n-i+1,m-i+1),i,0,n+1); %o A298309 (PARI) T(n,m) = sum(i=0, n+1, binomial(n-i+1,i-1)*binomial(n-i+1,i)*binomial(n-i+1,m-i+1)); %o A298309 tabl(nn) = for (n=0, nn, for (k=0, n, print1(T(n,k), ", ")); print()); \\ _Michel Marcus_, Jan 19 2018 %Y A298309 T(n,n) is A110320(n). %K A298309 nonn,tabl %O A298309 0,4 %A A298309 _Vladimir Kruchinin_, Jan 17 2018