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 A284293 #19 Jun 28 2025 19:53:33
%S A284293 1,6,11,16,61,66,111,116,161,166,611,616,661,666,1111,1116,1161,1166,
%T A284293 1611,1616,1661,1666,6111,6116,6161,6166,6611,6616,6661,6666,11111,
%U A284293 11116,11161,11166,11611,11616,11661,11666,16111,16116,16161,16166,16611,16616
%N A284293 Numbers using only digits 1 and 6.
%C A284293 Product of digits of n is a power of 6; subsequence of A276038.
%C A284293 Prime terms are in A020454.
%H A284293 Alois P. Heinz, <a href="/A284293/b284293.txt">Table of n, a(n) for n = 1..16382</a>
%t A284293 Join @@ (FromDigits /@ Tuples[{1,6}, #] & /@ Range[5]) (* _Giovanni Resta_, Mar 25 2017 *)
%o A284293 (Magma) [n: n in [1..20000] | Set(IntegerToSequence(n, 10)) subset {1, 6}];
%o A284293 (Python)
%o A284293 def A284293(n): return 5*int(bin(n+1)[3:])+(10**((n+1).bit_length()-1)-1)//9 # _Chai Wah Wu_, Jun 28 2025
%Y A284293 Cf. Numbers using only digits 1 and k for k = 0 and k = 2 - 9: A007088 (k = 0), A007931 (k = 2), A032917 (k = 3), A032822 (k = 4) , A276037 (k = 5), this sequence (k = 6), A276039 (k = 7), A213084 (k = 8), A284294 (k = 9).
%K A284293 nonn,base
%O A284293 1,2
%A A284293 _Jaroslav Krizek_, Mar 25 2017