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 A063004 #11 Apr 16 2023 15:55:41
%S A063004 0,1,5,1,11,49,17,115,473,217,1163,139,2465,11491,3299,26281,111611,
%T A063004 46075,269297,7153,545747,2685817,588665,5960299,26269505,9492289,
%U A063004 62031299,253202761,118985033,625390555,88519643,1339300753
%N A063004 Difference between 2^n and the next larger or equal power of 3.
%F A063004 a(n) = 3^ceiling(log_3(2^n)) - 2^n.
%t A063004 dp23[n_]:=Module[{t=2^n},3^Ceiling[Log[3,t]]-t]; Array[dp23,40,0] (* _Harvey P. Dale_, Nov 20 2015 *)
%o A063004 (PARI) for(n=1,50,print1(3^ceil(log(2^n)/log(3))-2^n","))
%Y A063004 Cf. A056577, A063003, A063005.
%K A063004 easy,nonn
%O A063004 0,3
%A A063004 _Jens Voß_, Jul 02 2001
%E A063004 More terms from _Ralf Stephan_, Mar 21 2003