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 A125231 #13 Nov 09 2019 02:02:56 %S A125231 1,1,1,1,2,2,1,3,6,2,1,4,12,8,3,1,5,20,20,15,3,1,6,30,40,45,18,4,1,7, %T A125231 42,70,105,63,28,4,1,8,56,112,210,168,112,32,5,1,9,72,168,378,378,336, %U A125231 144,45,5,1,10,90,240,630,756,840,480,225,50,6,1,11,110,330,990,1386,1848 %N A125231 Triangle read by rows: T(n,k) = ceiling((k+1)/2)*binomial(n,k) (0 <= k <= n). %C A125231 Row sums = A045623: (1, 2, 5, 12, 28, 64, 144, 320, ...). %C A125231 A125230 is another triangle with row sums = A045623. %e A125231 First few rows of the triangle: %e A125231 1; %e A125231 1, 1; %e A125231 1, 2, 2; %e A125231 1, 3, 6, 2; %e A125231 1, 4, 12, 8, 3; %e A125231 1, 5, 20, 20, 15, 3; %e A125231 1, 6, 30, 40, 45, 18, 4; %e A125231 1, 7, 42, 70, 105, 63, 28, 4; %e A125231 ... %p A125231 T:=(n,k)->ceil((k+1)/2)*binomial(n,k): for n from 0 to 12 do seq(T(n,k),k=0..n) od; # yields sequence in triangular form %t A125231 Flatten[Table[Ceiling[(k+1)/2]Binomial[n,k],{n,0,20},{k,0,n}]] (* _Harvey P. Dale_, Aug 31 2015 *) %Y A125231 Cf. A045623, A125230. %K A125231 nonn,tabl %O A125231 0,5 %A A125231 _Gary W. Adamson_, Nov 24 2006 %E A125231 Edited by _N. J. A. Sloane_, Dec 02 2006