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 A077720 #8 May 01 2018 14:23:57
%S A077720 7,37,43,223,1297,1303,1549,7993,9109,46663,54469,55987,281233,326593,
%T A077720 327889,335917,1679653,1679659,1679833,1680919,1681129,1687393,
%U A077720 1726273,1726489,1727569,1727827,1734049,1960891,1961107,1967587,2006461
%N A077720 Primes which can be expressed as sum of distinct powers of 6.
%C A077720 Primes whose base 6 representation contains only zeros and 1's.
%H A077720 Harvey P. Dale, <a href="/A077720/b077720.txt">Table of n, a(n) for n = 1..1000</a>
%t A077720 Select[FromDigits[#,6]&/@Tuples[{0,1},9],PrimeQ] (* _Harvey P. Dale_, May 01 2018 *)
%Y A077720 Cf. A020449, A000695, A033043, A077717, A077718, A077719, A077721, A077722.
%K A077720 nonn
%O A077720 1,1
%A A077720 _Amarnath Murthy_, Nov 19 2002
%E A077720 More terms from _Sascha Kurz_, Jan 03 2003