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 A074116 #18 Jan 18 2017 22:35:42
%S A074116 8,64,512,8192,65536,524288,8388608,67108864,536870912,8589934592,
%T A074116 68719476736,549755813888,8796093022208,70368744177664,
%U A074116 562949953421312,9007199254740992,72057594037927936,576460752303423488,9223372036854775808,73786976294838206464,590295810358705651712
%N A074116 Largest n-digit power of 2.
%C A074116 The exponents are given in A066343. - _Evgeny Kapun_, Jan 16 2017
%C A074116 An equivalent definition (which was formerly the definition of A074113): "Smallest n-digit number of the form p^a*q^b... with the maximum value of a+b+.... where p, q etc. are primes. If a,b,c,... are the indices in the signature prime factorization then a+b+c ... is a maximum." That this is the same sequence follows from the inequality p^a*q^b... >= 2^(a+b+...) and the fact that there always exists a power of 2 between two consecutive powers of 10.
%H A074116 Evgeny Kapun, <a href="/A074116/b074116.txt">Table of n, a(n) for n = 1..1000</a>
%F A074116 a(n) = 2^A066343(n).
%t A074116 Last[#]&/@(With[{l2=2^Range[80]},Table[Select[l2,IntegerLength[#] == n&], {n,22}]]) (* _Harvey P. Dale_, Jul 17 2011 *)
%Y A074116 Cf. A066343, A067488, A074113, A074114, A074117, A074118.
%K A074116 base,nonn
%O A074116 1,1
%A A074116 _Amarnath Murthy_, Aug 27 2002
%E A074116 Edited by _R. J. Mathar_, Feb 13 2008, _Max Alekseyev_, Mar 10 2009, _Harvey P. Dale_, Jul 17 2011, _Evgeny Kapun_, Jan 16 2017, and _N. J. A. Sloane_, Jan 18 2017