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 A265210 #18 Dec 06 2015 11:17:57
%S A265210 1,2,1,1,2,2,1,2,1,2,1,0,1,1,0,1,2,2,0,2,1,1,1,1,1,0,0,1,2,2,2,0,0,2,
%T A265210 1,2,2,1,0,1,1,2,1,2,0,1,2,2,1,0,2,1,2,1,2,1,2,0,1,0,2,0,2,0,1,1,1,2,
%U A265210 0,1,1,1,1,2,2,2,1,1,2,2,2,2,1,1
%N A265210 Irregular triangle read by rows in which row n lists the base 3 digits of 2^n in reverse order, n >= 0.
%C A265210 The length of row n is A020915(n) = 1 + A136409(n).
%C A265210 Conjecture 1: The sequence in column k is periodic, with period p(k) = 2*3^(k-1) = A008776(k-1), k >= 1, and in which the numbers 0,1,2 appear with equal frequency, for each k>1.
%e A265210 n
%e A265210 0: 1
%e A265210 1: 2
%e A265210 2: 1 1
%e A265210 3: 2 2
%e A265210 4: 1 2 1
%e A265210 5: 2 1 0 1
%e A265210 6: 1 0 1 2
%e A265210 7: 2 0 2 1 1
%e A265210 8: 1 1 1 0 0 1
%e A265210 9: 2 2 2 0 0 2
%e A265210 10: 1 2 2 1 0 1 1
%e A265210 11: 2 1 2 0 1 2 2
%e A265210 12: 1 0 2 1 2 1 2 1
%e A265210 13: 2 0 1 0 2 0 2 0 1
%e A265210 14: 1 1 2 0 1 1 1 1 2
%e A265210 15: 2 2 1 1 2 2 2 2 1 1
%t A265210 (* Replace Flatten with Grid to display the triangle: *)
%t A265210 Flatten[Table[Reverse[IntegerDigits[2^n, 3]], {n, 0, 15}]]
%o A265210 (PARI) A265210_row(n)=Vecrev(digits(2^n,3)) \\ _M. F. Hasler_, Dec 05 2015
%Y A265210 Cf. A000079 (powers of 2), A004642 (powers of 2 written in base 3), A008776 (2*3^n).
%Y A265210 Cf. A265209 (base 3 digits of 2^n).
%Y A265210 Cf. A264980 (row n read as ternary number).
%Y A265210 Cf. A037096 (numbers constructed from the inverse case, base 2 digits of 3^n).
%K A265210 nonn,tabf,base
%O A265210 0,2
%A A265210 _L. Edson Jeffery_, Dec 04 2015