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 A292473 #12 Oct 28 2017 09:58:27
%S A292473 2,3,11,5,23,29,7,37,43,157,13,41,47,173,113,17,59,53,181,151,223,19,
%T A292473 67,71,229,163,239
%N A292473 Square array read by antidiagonals downwards: A(n,k) = k-th prime p such that A001222(2^p-1) = n.
%C A292473 A permutation of the prime numbers.
%C A292473 Is this the same as k-th prime p such that A001221(2^p-1) = n?
%e A292473 Array starts
%e A292473 2, 3, 5, 7, 13, 17, ....
%e A292473 11, 23, 37, 41, 59, 67, ....
%e A292473 29, 43, 47, 53, 71, 73, ....
%e A292473 157, 173, 181, 229, 233, 263, ....
%e A292473 113, 151, 163, 191, 251, 307, ....
%e A292473 223, 239, 359, 463, 587, 641, ....
%e A292473 ....
%e A292473 A(2, 3) = 37, because the 3rd prime p such that 2^p-1 has 2 prime factors is 37, with 2^37-1 = 223 * 616318177.
%t A292473 With[{s = Array[PrimeOmega[2^Prime@ # - 1] &, 50]}, Function[t, Function[u, Table[Prime@ u[[#, k]] &[n - k + 1], {n, Length@t}, {k, n, 1, -1}]]@ Map[PadRight[#, Length@ t] &, t]]@ Values@ KeySort@ PositionIndex@ s] // Flatten (* _Michael De Vlieger_, Sep 17 2017 *)
%Y A292473 Cf. A000043 (row 1), A135978 (row 2), A140745 (column 1).
%Y A292473 Cf. A001222, A088863.
%K A292473 nonn,tabl,hard,more
%O A292473 1,1
%A A292473 _Felix Fröhlich_, Sep 17 2017
%E A292473 More terms from _Michael De Vlieger_, Sep 17 2017