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 A003063 #46 May 22 2024 12:55:10 %S A003063 -1,-1,1,11,49,179,601,1931,6049,18659,57001,173051,523249,1577939, %T A003063 4750201,14283371,42915649,128878019,386896201,1161212891,3484687249, %U A003063 10456158899,31372671001,94126401611,282395982049,847221500579,2541731610601,7625329049531,22876255584049 %N A003063 a(n) = 3^(n-1) - 2^n. %C A003063 Binomial transform of A000918: (-1, 0, 2, 6, 14, 30, ...). - _Gary W. Adamson_, Mar 23 2012 %C A003063 This sequence demonstrates 2^n as a loose lower bound for g(n) in Waring's problem. Since 3^n > 2(2^n) for all n > 2, the number 2^(n + 1) - 1 requires 2^n n-th powers for its representation since 3^n is not available for use in the sum: the gulf between the relevant powers of 2 and 3 widens considerably as n gets progressively larger. - _Alonso del Arte_, Feb 01 2013 %H A003063 Vincenzo Librandi, <a href="/A003063/b003063.txt">Table of n, a(n) for n = 1..1000</a> %H A003063 D. Knuth, <a href="/A003063/a003063.pdf">Letter to N. J. A. Sloane, date unknown</a> %H A003063 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (5,-6). %F A003063 Let b(n) = 2*(3/2)^n - 1. Then a(n) = -b(1-n)*3^(n-1) for n > 0. A083313(n) = A064686(n) = b(n)*2^(n-1) for n > 0. - _Michael Somos_, Aug 06 2006 %F A003063 From _Colin Barker_, May 27 2013: (Start) %F A003063 a(n) = 5*a(n-1) - 6*a(n-2). %F A003063 G.f.: -x*(1-4*x) / ((1-2*x)*(1-3*x)). (End) %F A003063 E.g.f.: (1/3)*(2 - 3*exp(2*x) + exp(3*x)). - _G. C. Greubel_, Nov 03 2022 %e A003063 a(3) = 1 because 3^2 - 2^3 = 9 - 8 = 1. %e A003063 a(4) = 11 because 3^3 - 2^4 = 27 - 16 = 11. %e A003063 a(5) = 49 because 3^4 - 2^5 = 81 - 32 = 49. %t A003063 Table[3^(n-1) - 2^n, {n, 25}] (* _Alonso del Arte_, Feb 01 2013 *) %t A003063 LinearRecurrence[{5,-6},{-1,-1},30] (* _Harvey P. Dale_, Feb 02 2015 *) %o A003063 (PARI) a(n)=3^(n-1)-2^n \\ _Charles R Greathouse IV_, Oct 07 2015 %o A003063 (Magma) [3^(n-1) -2^n: n in [1..30]]; // _G. C. Greubel_, Nov 03 2022 %o A003063 (SageMath) [3^(n-1) -2^n for n in range(1,31)] # _G. C. Greubel_, Nov 03 2022 %Y A003063 Cf. A000918, A056182 (first differences), A064686, A083313, A214091, A369490. %Y A003063 Cf. A363024 (prime terms). %Y A003063 From the third term onward the first differences of A005173. %Y A003063 Difference between two leftmost columns of A090888. %Y A003063 A diagonal in A254027. %Y A003063 Right edge of irregular triangle A252750. %K A003063 sign,easy %O A003063 1,4 %A A003063 Henrik Johansson (Henrik.Johansson(AT)Nexus.SE) %E A003063 A few more terms from _Alonso del Arte_, Feb 01 2013