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 A323856 #14 Feb 11 2019 02:05:48 %S A323856 1,16,177,1696,14995,126180,1025707,8133544,63274143,484966972, %T A323856 3672258385,27533213880,204715798387,1511417062948,11090886972237, %U A323856 80957709527896,588206815480213,4256231985648516,30685328305245631,220504966309520728,1579874958814261407 %N A323856 Sum of square displacements over all self-avoiding n-step walks on 4-d cubic lattice with first step specified, A242355(n)/8. %D A323856 For references and links see A010575 and A242355. %e A323856 a(1) = 1 is the square displacement of the fixed initial step. %e A323856 a(2) = 16, because one of the A010575(2)/8 = 7 end points is (2,0,0,0) with square distance 4 and the other 6 end points (1,-1,0,0), (1,1,0,0), (1,0,-1,0), (1,0,1,0), (1,0,0,-1), (1,0,0,1) all have square distance 2. 16 = 1*4 + 6*2. %e A323856 a(3) = 177, because there are 6 end points with square distance 1, e.g., (0,1,0,0), 24 end points with square distance 3, e.g., (1,1,1,0), 18 end points with square distance 5, e.g., (2,1,0,0), and 1 end point with square distance 9, (3,0,0,0). 177 = 6*1 + 24*3 + 18*5 + 1*9. %Y A323856 Cf. A010575, A078605, A118313, A242355, A323857. %K A323856 nonn,walk %O A323856 1,2 %A A323856 _Hugo Pfoertner_, Feb 03 2019