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 A133345 #26 Jan 01 2024 11:44:38 %S A133345 1,1,16,46,316,1276,6976,31816,161296,768016,3794176,18340576, %T A133345 89799616,436367296,2129929216,10369000576,50557010176,246280028416, %U A133345 1200358199296,5848636796416,28502288382976,138885491915776 %N A133345 a(n) = 2*a(n-1) + 14*a(n-2) for n>1, a(0)=1, a(1)=1. %C A133345 Binomial transform of A001024 (powers of 15), with interpolated zeros. %C A133345 a(n) is the number of compositions of n when there are 1 type of 1 and 15 types of other natural numbers. - _Milan Janjic_, Aug 13 2010 %H A133345 G. C. Greubel, <a href="/A133345/b133345.txt">Table of n, a(n) for n = 0..1000</a> %H A133345 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (2,14). %F A133345 G.f.: (1-x)/(1-2*x-14*x^2). %F A133345 a(n) = Sum_{k=0..n} A098158(n,k)*15^(n-k). - _Philippe Deléham_, Dec 26 2007 %F A133345 If p[1]=1, and p[i]=15, (i>1), and if A is Hessenberg matrix of order n defined by: A[i,j]=p[j-i+1], (i<=j), A[i,j]=-1, (i=j+1), and A[i,j]=0 otherwise. Then, for n>=1, a(n)=det A. - _Milan Janjic_, Apr 29 2010 %F A133345 a(n) = (b*i)^(n-1)*(b*i*ChebyshevU(n, -i/b) - ChebyshevU(n-1, -i/b)), with b = sqrt(14). - _G. C. Greubel_, Oct 15 2022 %t A133345 LinearRecurrence[{2,14},{1,1},30] (* _Harvey P. Dale_, Jan 07 2016 *) %o A133345 (PARI) Vec((1-x)/(1-2*x-14*x^2)+O(x^99)) \\ _Charles R Greathouse IV_, Jan 12 2012 %o A133345 (Magma) [n le 2 select 1 else 2*(Self(n-1) +7*Self(n-2)): n in [1..41]]; // _G. C. Greubel_, Oct 15 2022 %o A133345 (SageMath) %o A133345 A133345=BinaryRecurrenceSequence(2,14,1,1) %o A133345 [A133345(n) for n in range(41)] # _G. C. Greubel_, Oct 15 2022 %Y A133345 Cf. A001024, A098158. %K A133345 nonn,easy %O A133345 0,3 %A A133345 _Philippe Deléham_, Dec 21 2007