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 A288097 #9 Jan 21 2023 13:21:27
%S A288097 1093,2,11,1093,71,2,2,3,1093,5,1093,11,2,2,71,2,71,1093,1093,3,2,
%T A288097 1093,3,2,2,11,1093,2,2,11,1093,1093,71,2,1093,3,1093,71,2,2,3,1093,2,
%U A288097 11,13,2,3,1093,1093,11,2,1093,71,2,2,1093,11,2,2,71,1093,2,3,1093,1093,7
%N A288097 Square array read by antidiagonals downwards: A(n, 1) = smallest base-prime(n) Wieferich prime and A(n, k) = smallest base-A(n, k-1) Wieferich prime for k > 1.
%e A288097 Array starts
%e A288097 1093, 2, 1093, 2, 1093, 2, 1093, 2, 1093, 2
%e A288097 11, 71, 3, 11, 71, 3, 11, 71, 3, 11
%e A288097 2, 1093, 2, 1093, 2, 1093, 2, 1093, 2, 1093
%e A288097 5, 2, 1093, 2, 1093, 2, 1093, 2, 1093, 2
%e A288097 71, 3, 11, 71, 3, 11, 71, 3, 11, 71
%e A288097 2, 1093, 2, 1093, 2, 1093, 2, 1093, 2, 1093
%e A288097 2, 1093, 2, 1093, 2, 1093, 2, 1093, 2, 1093
%e A288097 3, 11, 71, 3, 11, 71, 3, 11, 71, 3
%e A288097 13, 2, 1093, 2, 1093, 2, 1093, 2, 1093, 2
%e A288097 2, 1093, 2, 1093, 2, 1093, 2, 1093, 2, 1093
%t A288097 f[n_] := Block[{p = 2}, While[! Divisible[n^(p - 1) - 1, p^2], p = NextPrime@ p]; p]; T[n_, k_] := T[n, k] = If[k == 1, f@ Prime@ n, f@ T[n, k - 1]]; Table[Function[n, T[n, k]][m - k + 1], {m, 12}, {k, m, 1, -1}] // Flatten (* _Michael De Vlieger_, Jun 06 2017 *)
%o A288097 (PARI) a039951(n) = forprime(p=1, , if(Mod(n, p^2)^(p-1)==1, return(p)))
%o A288097 table(rows, cols) = forprime(p=1, prime(rows), my(i=0, w=a039951(p)); while(i < cols, print1(w, ", "); w=a039951(w); i++); print(""))
%o A288097 table(10, 10) \\ print initial 10 rows and 10 columns of table
%Y A288097 Cf. A039951, A252801, A252802, A252812, A269111, A281001, A281002, A268479.
%K A288097 nonn,tabl
%O A288097 1,1
%A A288097 _Felix Fröhlich_, Jun 05 2017
%E A288097 More terms from _Michael De Vlieger_, Jun 06 2017