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A166023 a(n) = 6*a(n-2) for n > 2; a(1) = 1, a(2) = 5.

%I A166023 #12 Jun 30 2023 14:25:24
%S A166023 1,5,6,30,36,180,216,1080,1296,6480,7776,38880,46656,233280,279936,
%T A166023 1399680,1679616,8398080,10077696,50388480,60466176,302330880,
%U A166023 362797056,1813985280,2176782336,10883911680,13060694016,65303470080,78364164096
%N A166023 a(n) = 6*a(n-2) for n > 2; a(1) = 1, a(2) = 5.
%C A166023 Interleaving of A000400 and 5*A000400.
%C A166023 Fifth binomial transform is A154236.
%H A166023 Vincenzo Librandi, <a href="/A166023/b166023.txt">Table of n, a(n) for n = 1..300</a>
%H A166023 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (0, 6).
%F A166023 a(n) = 6^(1/4*(2*n+3+(-1)^n))*(11-(-1)^n)/72.
%F A166023 G.f.: x*(1+5*x)/(1-6*x^2).
%t A166023 LinearRecurrence[{0, 6}, {1, 5}, {1, 50}] (* _G. C. Greubel_, Apr 21 2016 *)
%o A166023 (Magma) [ n le 2 select 4*n-3 else 6*Self(n-2): n in [1..29] ];
%Y A166023 Cf. A000400 (powers of 6), A154236.
%K A166023 nonn,easy
%O A166023 1,2
%A A166023 _Klaus Brockhaus_, Oct 04 2009