%I #18 Sep 04 2024 13:23:14
%S 2,7,57,19552,680483009297,912636103453654574831532134829167,
%T 133568351664635266141573629327103053181254256064476277123035496133898909306737386958053448197
%N a(n+1) = a(n) converted to base 7 from base 2 (written in base 10).
%C The next term (a(8)) has 259 digits. - _Harvey P. Dale_, Sep 04 2024
%H John Cerkan, <a href="/A023364/b023364.txt">Table of n, a(n) for n = 1..9</a>
%t NestList[FromDigits[IntegerDigits[#,2],7]&,2 ,6] (* _Harvey P. Dale_, Sep 04 2024 *)
%K nonn,base
%O 1,1
%A _David W. Wilson_
%E a(7) from _Sean A. Irvine_, Jun 02 2019