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 A105373 #15 May 20 2025 08:26:27 %S A105373 1,1,1,1,6,1,1,28,8,1,1,120,49,10,1,1,496,272,76,12,1,1,2016,1441,520, %T A105373 109,14,1,1,8128,7448,3376,888,148,16,1,1,32640,37969,21280,6841,1400, %U A105373 193,18,1,1,130816,192032,131776,51012,12496,2080,244,20,1,1,523776 %N A105373 Square array by antidiagonals of number of straight lines with n points in a k-dimensional hypercube with n points on each edge. %F A105373 T(1, k)=1. For n>1: T(n, k) = ((n+2)^k-n^k)/2 = (n+2)*T(n, k-1)+n^(k-1) = A102728(k, n+1). %e A105373 Rows start: %e A105373 1, 1, 1, 1, 1, 1, ...; %e A105373 1, 6, 28, 120, 496, 2016, ...; %e A105373 1, 8, 49, 272, 1441, 7448, ...; %e A105373 1, 10, 76, 520, 3376, 21280, ...; %e A105373 1, 12, 109, 888, 6841, 51012, ...; %e A105373 etc. %e A105373 T(5,3)=109 because in a 5 X 5 X 5 cube there are 25 columns, 25 linear rows in one direction, 25 linear rows in another direction, 5 short diagonals in each of 6 directions and 4 long diagonals; and 3*25 + 6*5 + 4 = 109. %Y A105373 See A102728. Rows essentially include A000012, A006516, A005059, A016149 or A081199, A016161 or A081200, A016170 or A081201, A016178 or A081202 etc. Columns essentially include A000012, A005843, A056107, A105373. %K A105373 nonn,tabl %O A105373 1,5 %A A105373 _Henry Bottomley_, Apr 02 2005