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 A079653 #7 Aug 18 2020 04:23:13
%S A079653 0,3,6,36,66,300,630,666,903,990,3003,6903,33930,39060,39903,63903,
%T A079653 66066,69006,93096,306936,333336,339900,600060,609960,630003,669903,
%U A079653 690900,833986,930930,936396,963966,3036880,3069003,3083886,3306306,3689686,3966336,3988900
%N A079653 Triangular numbers using only the curved digits 0, 3, 6, 8 and 9.
%H A079653 Amiram Eldar, <a href="/A079653/b079653.txt">Table of n, a(n) for n = 1..10000</a>
%t A079653 t[n_] := n*(n + 1)/2; t /@ Select[Range[0, 10000], AllTrue[IntegerDigits[t[#]], MemberQ[{0, 3, 6, 8 , 9}, #1] &] &] (* _Amiram Eldar_, Aug 18 2020 *)
%Y A079653 Intersection of A000217 and A072960.
%K A079653 base,nonn
%O A079653 1,2
%A A079653 _Shyam Sunder Gupta_, Jan 23 2003
%E A079653 a(1) = 0 and more terms from _Amiram Eldar_, Aug 18 2020