login
Expansion of g.f.: (1+x)/(1-23*x).
50

%I #26 Sep 08 2022 08:45:49

%S 1,24,552,12696,292008,6716184,154472232,3552861336,81715810728,

%T 1879463646744,43227663875112,994236269127576,22867434189934248,

%U 525950986368487704,12096872686475217192,278228071788929995416,6399245651145389894568,147182649976343967575064

%N Expansion of g.f.: (1+x)/(1-23*x).

%H Kenny Lau, <a href="/A170743/b170743.txt">Table of n, a(n) for n = 0..733</a>

%H <a href="/index/Rec#order_01">Index entries for linear recurrences with constant coefficients</a>, signature (23).

%F a(n) = Sum_{k=0..n} A097805(n,k)*(-1)^(n-k)*24^k. - _Philippe Deléham_, Dec 04 2009

%F a(0) = 1; for n>0, a(n) = 24*23^(n-1). - _Vincenzo Librandi_, Dec 05 2009

%F E.g.f.: (24*exp(23*x) -1)/23. - _G. C. Greubel_, Sep 25 2019

%p k:=24; seq(`if`(n=0, 1, k*(k-1)^(n-1)), n = 0..25); # _G. C. Greubel_, Sep 25 2019

%t CoefficientList[Series[(1+x)/(1-23x),{x,0,20}],x] (* or *) LinearRecurrence[ {23},{1,24},20] (* or *) Join[{1},NestList[ 23#&,24,20]] (* _Harvey P. Dale_, Oct 21 2015 *)

%o (Python) for i in range(1001):print(i,24*23**(i-1) if i>0 else 1) # _Kenny Lau_, Aug 02 2017

%o (PARI) Vec((1+x)/(1-23*x) + O(x^18)) \\ _Felix Fröhlich_, Aug 02 2017

%o (Magma) k:=24; [1] cat [k*(k-1)^(n-1): n in [1..25]]; // _G. C. Greubel_, Sep 25 2019

%o (Sage) k=24; [1]+[k*(k-1)^(n-1) for n in (1..25)] # _G. C. Greubel_, Sep 25 2019

%o (GAP) k:=24;; Concatenation([1], List([1..25], n-> k*(k-1)^(n-1) )); # _G. C. Greubel_, Sep 25 2019

%Y Cf. A003945, A097805.

%K nonn,easy

%O 0,2

%A _N. J. A. Sloane_, Dec 04 2009