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 A065713 #32 Dec 04 2024 15:40:25
%S A065713 1,4,7,10,13,7,19,22,25,19,31,25,37,40,43,37,58,61,64,67,61,46,58,70,
%T A065713 73,76,79,82,85,70,82,85,88,109,103,70,109,130,106,100,112,124,118,
%U A065713 112,115,118,139,151,127,112,115,118,121,142,145,121,160
%N A065713 Sum of digits of 4^n.
%H A065713 Harry J. Smith, <a href="/A065713/b065713.txt">Table of n, a(n) for n = 0..1000</a>
%F A065713 a(n) = A007953(A000302(n)). - _Michel Marcus_, Nov 01 2013 [corrected by _Georg Fischer_, Dec 19 2020]
%F A065713 a(n) = A001370(2n). Results given there imply a(n) > log_4(n) + 1/2, n > 0, but we can conjecture & expect a(n) ~ 9*log_10(2)*n. - _M. F. Hasler_, May 18 2017
%t A065713 Table[Total[IntegerDigits[4^n]], {n, 0, 60}] (* _Vincenzo Librandi_, Oct 08 2013 *)
%o A065713 (PARI) a065713(n)=sumdigits(4^n); \\ _Michel Marcus_, Nov 01 2013
%Y A065713 Cf. A000302, A007953.
%Y A065713 Cf. sum of digits of k^n: A001370 (k=2), A004166 (k=3), this sequence (k=4), A066001 (k=5), A066002 (k=6), A066003(k=7), A066004 (k=8), A065999 (k=9), A066005 (k=11), A066006 (k=12), A175527 (k=13).
%K A065713 nonn,base
%O A065713 0,2
%A A065713 _N. J. A. Sloane_, Dec 11 2001