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 A274883 #12 Jul 14 2016 10:40:03 %S A274883 1,1,2,1,4,4,3,6,12,8,2,24,24,32,16,10,20,120,80,80,32,5,120,120,480, %T A274883 240,192,64,35,70,840,560,1680,672,448,128,14,560,560,4480,2240,5376, %U A274883 1792,1024,256,126,252,5040,3360,20160,8064,16128,4608,2304,512 %N A274883 Triangle read by rows, T(n,k) = 2^k*binomial(n,k)*A057977(n-k) for n>=0 and 0<=k<=n. %e A274883 Triangle starts: %e A274883 1; %e A274883 1, 2; %e A274883 1, 4, 4; %e A274883 3, 6, 12, 8; %e A274883 2, 24, 24, 32, 16; %e A274883 10, 20, 120, 80, 80, 32; %e A274883 5, 120, 120, 480, 240, 192, 64; %e A274883 35, 70, 840, 560, 1680, 672, 448, 128; %e A274883 14, 560, 560, 4480, 2240, 5376, 1792, 1024, 256; %p A274883 T := (n,k) -> 2^k*binomial(n,k)*((n-k)!/floor((n-k)/2)!^2)/(floor((n-k)/2)+1); %p A274883 seq(seq(T(n,k), k=0..n), n=0..9); %Y A274883 Cf. A000079 (T(n,n)), A057977 (T(n,0)), A077587 (row sum). %Y A274883 Cf. A189912. Row reversed A091894 is a subtriangle. %K A274883 nonn,tabl %O A274883 0,3 %A A274883 _Peter Luschny_, Jul 14 2016