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 A125666 #25 Jul 09 2024 20:11:20
%S A125666 2,6,3,30,10,4,210,42,12,5,2310,330,60,14,7,30030,2730,390,66,15,8,
%T A125666 510510,39270,3570,420,70,18,9,9699690,570570,43890,3990,462,78,20,11,
%U A125666 223092870,11741730,690690,46410,4290,510,84,21,13,6469693230,281291010
%N A125666 Table read by ascending antidiagonals: n-th row of table consists of the positive integers divisible by exactly n distinct primes.
%C A125666 Concatenated sequence is a permutation of the integers >= 2.
%C A125666 The chosen encoding of the table by *rising* antidiagonals is contrary to the OEIS standard which rather expects falling antidiagonals: as a consequence, displaying this sequence as a table (2nd link after the list of terms above) will list the integers with given number of prime divisors in columns rather than rows. - _M. F. Hasler_, Jun 06 2024
%e A125666 The table begins:
%e A125666 n\k| 1 2 3 4 5 6 ...
%e A125666 ---+-------------------------------------
%e A125666 1 | 2, 3, 4, 5, 7, 8, ...
%e A125666 2 | 6, 10, 12, 14, 15, ...
%e A125666 3 | 30, 42, 60, 66, ...
%e A125666 4 | 210, 330, 390, ...
%e A125666 5 | 2310, 2730, ...
%e A125666 6 | 30030, ...
%e A125666 ...| ...
%t A125666 f[n_, m_] := f[n, m] = Block[{c = m, k = If[m == 1, Product[Prime[i], {i, n}], f[n, m - 1] + 1]},While[Length@FactorInteger[k] != n, k++ ];k];Table[f[d - m + 1, m], {d, 10}, {m, d}] // Flatten (* _Ray Chandler_, Feb 08 2007 *)
%o A125666 (PARI) A125666(n, k=0)={if(k, for(m=vecprod(primes(n)), oo, omega(m)!=n || k-- || return(m)), A125666(A004736(n), A002260(n)))} \\ _M. F. Hasler_, Jun 06 2024
%Y A125666 Cf. A001221, A002110 (col 1), A246655 (row 1), A007774 (row 2), A033992 (row 3), A033993 (row 4), A051270 (row 5), A074969 (row 6), A176655 (row 7), A348072 (row 8), A348073 (row 9), A073329 (diag), compare to A048692.
%K A125666 nonn,tabl
%O A125666 1,1
%A A125666 _Leroy Quet_, Jan 29 2007
%E A125666 Extended by _Ray Chandler_, Feb 08 2007