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 A067419 #20 Sep 06 2024 08:06:47 %S A067419 1,6,72,864,10368,124416,1492992,17915904,214990848,2579890176, %T A067419 30958682112,371504185344,4458050224128,53496602689536, %U A067419 641959232274432,7703510787293184,92442129447518208,1109305553370218496,13311666640442621952,159739999685311463424 %N A067419 Fourth column of triangle A067417. %H A067419 Vincenzo Librandi, <a href="/A067419/b067419.txt">Table of n, a(n) for n = 0..900</a> %H A067419 <a href="/index/Rec#order_01">Index entries for linear recurrences with constant coefficients</a>, signature (12). %F A067419 a(n) = A067417(n+3, 3). %F A067419 a(n) = 6*(3*4)^(n-1), n >= 1, a(0)=1. %F A067419 G.f.: (1-6*x)/(1-12*x). %F A067419 a(n) = Sum_{k=0..n} A134309(n,k)*6^k = Sum_{k=0..n} A055372(n,k)*5^k. - _Philippe Deléham_, Feb 04 2012 %t A067419 Join[{1}, NestList[12*# &, 6, 20]] (* _Paolo Xausa_, Sep 03 2024 *) %o A067419 (Magma) [Ceiling(6*(3*4)^(n-1)): n in [0..20]]; // _Vincenzo Librandi_, Oct 02 2011 %Y A067419 Cf. A067403 (third column), A067420 (fifth column), A001021 (powers of 12). %K A067419 nonn,easy %O A067419 0,2 %A A067419 _Wolfdieter Lang_, Jan 25 2002