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 A051289 #20 Aug 13 2024 04:59:46 %S A051289 1,2,1,4,4,2,8,12,12,3,16,32,48,24,6,32,80,160,120,60,10,64,192,480, %T A051289 480,360,120,20,128,448,1344,1680,1680,840,280,35,256,1024,3584,5376, %U A051289 6720,4480,2240,560,70,512,2304,9216,16128,24192 %N A051289 Triangular array T read by rows: T(n,k)=P(2n+1,n,2k+1), where P(n,k,c)=number of vectors (x(1),x(2,),...,x(n)) of k 1's and n-k 0's such that x(i)=x(n+1-i) for exactly c values of i. %C A051289 P(n,k,n) counts palindromes. %F A051289 E.g.f.: exp(2*y)*(BesselI(0, 2*x*y)+BesselI(1, 2*x*y)). - _Vladeta Jovovic_, Dec 15 2004 %e A051289 Triangle begins: %e A051289 1; %e A051289 2, 1; %e A051289 4, 4, 2; %e A051289 8, 12, 12, 3; %e A051289 16, 32, 48, 24, 6; %e A051289 ... %Y A051289 Cf. A001700 (row sums), A051287, A051288, A051290. %K A051289 nonn,tabl %O A051289 0,2 %A A051289 _Clark Kimberling_