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 A240554 #5 Apr 08 2014 03:02:52
%S A240554 1,2,1,3,2,1,2,5,2,1,5,5,3,2,1,3,17,7,17,2,1,7,13,13,41,11,2,1,2,37,7,
%T A240554 257,61,13,2,1,3,5,31,313,41,73,43,2,1,5,13,43,1297,521,241,547,257,2,
%U A240554 1,11,41,19,1201,101,601,113,193,19,2,1,3,101,73,241
%N A240554 Square array of the greatest prime factor of n^k + 1, read by antidiagonals.
%H A240554 T. D. Noe, <a href="/A240554/b240554.txt">Rows n = 1..60 of triangle, flattened</a>
%t A240554 Table[FactorInteger[(n-k)^k + 1][[-1,1]], {n, 12}, {k, n}]
%Y A240554 Cf. A003992 (n^k), A014442 (k=2), A081256 (k=3), A096172 (k=4).
%Y A240554 Cf. A240548-A240553 (k=5 to 10).
%K A240554 nonn,tabl
%O A240554 1,2
%A A240554 _T. D. Noe_, Apr 07 2014