cp's OEIS Frontend

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.

A089507 Second column of triangle A089504 and second column of array A078741 divided by 18.

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%I A089507 #17 Sep 08 2022 08:45:12
%S A089507 1,30,756,18360,441936,10614240,254788416,6115201920,146766525696,
%T A089507 3522406694400,84537821131776,2028908069959680,48693795855814656,
%U A089507 1168651113600245760,28047626804770062336,673143043784666480640
%N A089507 Second column of triangle A089504 and second column of array A078741 divided by 18.
%C A089507 Convolution of A000400 (powers of 6) with A009968 (powers of 24).
%H A089507 Vincenzo Librandi, <a href="/A089507/b089507.txt">Table of n, a(n) for n = 0..730</a>
%H A089507 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (30,-144).
%F A089507 G.f.: 1/((1-3*2*1*x)*(1-4*3*2*x)).
%F A089507 a(n) = A089504(n+2, 2), n>=0.
%F A089507 a(n) = (4*(4*3*2)^n - (3*2*1)^n)/3 = (2^n)*(2^(2*(n+1))-1)*3^(n-1).
%F A089507 a(n) = 6^n*(4^(n+1)-1)/3. - _Vincenzo Librandi_, Oct 18 2017
%t A089507 CoefficientList[Series[1/((1-6x)(1-24x)),{x,0,20}],x] (* or *) LinearRecurrence[{30,-144},{1,30},20] (* _Harvey P. Dale_, Sep 25 2017 *)
%o A089507 (Magma) [6^n*(4^(n+1)-1)/3: n in [0..15]]; // _Vincenzo Librandi_, Oct 18 2017
%Y A089507 Cf. A089505, A089513, A089514.
%K A089507 nonn,easy
%O A089507 0,2
%A A089507 _Wolfdieter Lang_, Dec 01 2003