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 A058967 #5 Mar 08 2018 12:17:11
%S A058967 1,2,10,30,78,190,508,1210,2744,6070,13236,28594,61360,130990,278444,
%T A058967 589738,1245096,2621350,5504932,11534242,24117152,50331550,104857500,
%U A058967 218103706,452984728,939523990,1946156948,4026531730,8321499024
%N A058967 If n < 8 then A058966(n), else n*2^(n - 3) - 2*n - 50.
%D A058967 B. Elspas, The theory of multirail cascades, in A. Mukhopadhyay, ed., Recent Developments in Switching Theory, Ac. Press, 1971, Chap. 8, see esp. p. 362 (S_2(n)).
%t A058967 Table[Which[n==3,1,n<8,n*2^(n-3)-2^(n-2)-2,True,n*2^(n-3)-2n-50],{n,3,40}] (* _Harvey P. Dale_, Mar 08 2018 *)
%K A058967 nonn
%O A058967 3,2
%A A058967 _N. J. A. Sloane_, Jan 14 2001