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 A193760 #12 Mar 05 2019 00:27:59 %S A193760 1,2,3,5,7,12,15,18,81,101,123,156,183,212,255,289,325,648,723,802, %T A193760 903,991,1083,1200,1301,1406,19683,21953,24391,27030,29823,32802 %N A193760 Replace 3^i with n^i in ternary representation of n. %p A193760 A193760 := proc(n) nb3 := convert(n,base,3) ; add(op(i,nb3)*n^(i-1),i=1..nops(nb3)) ; end proc: seq(A193760(n),n=1..40) ; # _R. J. Mathar_, Aug 05 2011 %o A193760 (Sage) def A193760(n): return sum(d*n**i for i,d in enumerate(n.digits(base=3))) # _D. S. McNeil_, Aug 05 2011 %Y A193760 Cf. A104258 for the sequence formed by the binary rather than ternary numbers. %K A193760 nonn,base %O A193760 1,2 %A A193760 _John Frye_, Aug 04 2011