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 A358739 #11 Dec 15 2022 14:02:24 %S A358739 2,6,10,84,210,218,5040,19740,15330,25426,1249920,5780880,6939660, %T A358739 7604610,11979362,1259919360,7533267840,9297061200,12276675180, %U A358739 14280964866,24071588290,5120312279040,34082078607360,48312946523520,78970351980240,88215877158444,112601184828930,195647202043778 %N A358739 Triangular array read by rows. T(n,k) is the number of n X n matrices A over F_2 such that Sum_{phi} nullity(phi(A)) = k where the sum is over all monic irreducible polynomials in F_2[x] that divide the characteristic polynomial of A, n >= 1, 1 <= k <= n. %e A358739 Triangle begins %e A358739 2; %e A358739 6, 10; %e A358739 84, 210, 218; %e A358739 5040, 19740, 15330, 25426; %e A358739 1249920, 5780880, 6939660, 7604610, 11979362; %e A358739 ... %Y A358739 Cf. A346222 (main diagonal), A083402 (1/2 * column 1), A002416 (row sums). %K A358739 nonn,tabl %O A358739 1,1 %A A358739 _Geoffrey Critzer_, Nov 29 2022