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 A066006 #21 Dec 04 2024 15:39:48
%S A066006 1,3,9,18,18,27,45,36,54,45,45,54,54,63,81,72,90,72,81,117,108,90,99,
%T A066006 99,117,117,135,153,135,135,153,180,153,117,117,180,171,171,189,198,
%U A066006 216,198,225,225,216,198,225,234,252,234,216,234,279,243
%N A066006 Sum of digits of 12^n.
%H A066006 Harry J. Smith, <a href="/A066006/b066006.txt">Table of n, a(n) for n = 0..1000</a>
%F A066006 a(n) = A007953(A001021(n)). - _Michel Marcus_, Nov 01 2013
%t A066006 Table[Total[IntegerDigits[12^n]], {n, 0, 60}] (* _Vincenzo Librandi_, Oct 08 2013 *)
%o A066006 (PARI) a(n) = sumdigits(12^n); \\ _Michel Marcus_, Nov 01 2013
%Y A066006 Cf. sum of digits of k^n: A001370 (k=2), A004166 (k=3), A065713 (k=4), A066001 (k=5), A066002 (k=6), A066003(k=7), A066004 (k=8), A065999 (k=9), A066005 (k=11), this sequence (k=12), A175527 (k=13).
%K A066006 nonn,base
%O A066006 0,2
%A A066006 _N. J. A. Sloane_, Dec 11 2001