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 A127947 #12 Sep 08 2022 08:45:29
%S A127947 1,10,500,125000,156250000,976562500000,30517578125000000,
%T A127947 4768371582031250000000,3725290298461914062500000000,
%U A127947 14551915228366851806640625000000000
%N A127947 Hankel transform of central coefficients of (1+k*x+5x^2)^n, k arbitrary integer.
%C A127947 Hankel transform of A098264. The Hankel transform of e.g.f. Bessel_I(0,2*sqrt(5)x) and its k-th binomial transforms, are given by a(n). In general, the Hankel transform of e.g.f. Bessel_I(0,2*sqrt(m)x) and its binomial transforms is 2^n*m^C(n+1,2).
%H A127947 G. C. Greubel, <a href="/A127947/b127947.txt">Table of n, a(n) for n = 0..52</a>
%F A127947 a(n) = 2^n*5^C(n+1,2).
%t A127947 Table[2^n*5^Binomial[n+1,2], {n,0,30}] (* _G. C. Greubel_, May 03 2018 *)
%o A127947 (PARI) for(n=0, 30, print1(2^n*5^binomial(n+1,2), ", ")) \\ _G. C. Greubel_, May 03 2018
%o A127947 (Magma) [2^n*5^Binomial(n+1,2): n in [0..30]]; // _G. C. Greubel_, May 03 2018
%K A127947 easy,nonn
%O A127947 0,2
%A A127947 _Paul Barry_, Feb 08 2007