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 A260043 #9 Jul 22 2015 22:39:01 %S A260043 0,1,0,0,4,4,1,0,0,0,6,45,90,78,36,9,1,0,0,0,0,8,96,576,2128,4860,676, %T A260043 6496,4080,1796,560,120,16,1,0,0,0,0,0,10,200,1900,11500,50025,166720, %U A260043 439600,923700,1534800,1994200,2010920,1571525,956775,458500,174700,53010,12650,2300,300,25,1 %N A260043 Irregular triangle read by rows: T(n,k) (n >= 1, 0 <= k <= n^2) = number of n X n (0,1) real matrices with k zeros and permanent zero. %D A260043 M. B. Wells, Elements of Combinatorial Computing. Pergamon, Oxford, 1971, see p. 240. %H A260043 M. B. Wells, <a href="/A000170/a000170.pdf">Elements of Combinatorial Computing</a>, Pergamon, Oxford, 1971. [Annotated scanned copy of pages 237-240] %e A260043 Triangle begins: %e A260043 0,1, %e A260043 0,0,4,4,1, %e A260043 0,0,0,6,45,90,78,36,9,1, %e A260043 0,0,0,0,8,96,576,2128,4860,676,6496,4080,1796,560,120,16,1, %e A260043 0,0,0,0,0,10,200,1900,11500,50025,166720,439600,923700,1534800,1994200,2010920,1571525,956775,458500,174700,53010,12650,2300,300,25,1, %e A260043 ... %K A260043 nonn,tabf %O A260043 1,5 %A A260043 _N. J. A. Sloane_, Jul 22 2015