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 A077029 #12 Oct 25 2021 11:10:32 %S A077029 1,1,0,1,1,0,1,2,0,0,1,3,1,0,0,1,4,3,0,0,0,1,5,5,1,0,0,0,1,6,7,4,0,0, %T A077029 0,0,1,7,9,7,1,0,0,0,0,1,8,11,10,5,0,0,0,0,0,1,9,13,13,9,1,0,0,0,0,0, %U A077029 1,10,15,16,13,6,0,0,0,0,0,0,1,11,17,19,17,11,1,0,0,0,0,0,0,1,12,19,22,21,16,7,0,0,0,0,0,0,0 %N A077029 Rectangle R(i,j) read by ascending antidiagonals: column j has j-1 zeros followed by numbers congruent to 1 mod j-1. %C A077029 The number of occurrences of k is the number of divisors of k-1, for k>=2. Column 1 of the inverse of this infinite matrix begins with (1,-1,1,-1,2,-6,24,-120,6!,-7!,8!,-9!,...). The remaining columns are likewise expressible in terms of factorials. %F A077029 R(i, j) = (i-j)*(j-1)+1 if 1<=j<=i; R(i, j)=0 if j>=i+1. %e A077029 Northwest corner: %e A077029 1 0 0 0 0 0 %e A077029 1 1 0 0 0 0 %e A077029 1 2 1 0 0 0 %e A077029 1 3 3 1 0 0 %e A077029 1 4 5 4 1 0 %e A077029 1 5 7 7 5 1 %Y A077029 Cf. A077028. %K A077029 nonn,tabl %O A077029 1,8 %A A077029 _Clark Kimberling_, Oct 19 2002 %E A077029 Definition amended by _Georg Fischer_, Oct 25 2021