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 A354446 #46 Mar 10 2025 14:49:46
%S A354446 30,506,606,715,1558,1730,3945,5083,6365,8558,9361,11986,12455,14935,
%T A354446 15458,17081,19371,19966,21183,25726,29971,32215,32981,37766,45551,
%U A354446 46461,51146,54065,57065,58083,62245,68758,74433,75595,76766,80333,86458,88971,90241
%N A354446 11-gonal numbers which are products of three distinct primes.
%C A354446 A squarefree subsequence of 11-gonal numbers.
%e A354446 30 = 3*(9*3 - 7)/2 = 2 * 3 * 5;
%e A354446 506 = 11*(9*11 - 7)/2 = 2 * 11 * 23;
%e A354446 3945 = 30*(9*30 - 7)/2 = 3 * 5 * 263;
%e A354446 80333 = 134*(9*134 - 7)/2 = 11 * 67 * 109.
%p A354446 q:= n-> is(map(x-> x[2], ifactors(n)[2])=[1$3]):
%p A354446 select(q, [n*(9*n-7)/2$n=1..200])[]; # _Alois P. Heinz_, Jun 15 2022
%t A354446 Select[Table[n*(9*n-7)/2, {n, 1, 150}], FactorInteger[#][[;; , 2]]=={1, 1, 1} &] (* _Amiram Eldar_, Jun 01 2022 *)
%Y A354446 Intersection of A051682 and A007304.
%K A354446 nonn
%O A354446 1,1
%A A354446 _Massimo Kofler_, Jun 01 2022