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A197194 a(n) = binomial(n+9, 9)*9^n. 1

%I #23 Apr 17 2022 08:23:12

%S 1,90,4455,160380,4691115,118216098,2659862205,54717165360,

%T 1046465787510,18836384175180,322102169395578,5270762771927640,

%U 83014513657860330,1264374900327411180,18694686026269579590,269203478778281946096,3785673920319589866975,52108688079693178168950,703467289075857905280825

%N a(n) = binomial(n+9, 9)*9^n.

%H Vincenzo Librandi, <a href="/A197194/b197194.txt">Table of n, a(n) for n = 0..400</a>

%F a(n) = C(n + 9, 9)*9^n.

%F G.f.: 1 / (9*x-1)^10 . - _R. J. Mathar_, Oct 13 2011

%F From _Amiram Eldar_, Apr 17 2022: (Start)

%F Sum_{n>=0} 1/a(n) = 1358954496*log(9/8) - 44817299757/280.

%F Sum_{n>=0} (-1)^n/a(n) = 8100000000*log(10/9) - 47791529847/56. (End)

%t Table[Binomial[n+9,9]9^n,{n,0,20}] (* _Harvey P. Dale_, Feb 22 2020 *)

%o (Magma) [Binomial(n+9, 9)*9^n: n in [0..20]];

%o (Python)

%o A197194_list, m, k = [], [1]*10, 1

%o for _ in range(10**2):

%o A197194_list.append(k*m[-1])

%o k *= 9

%o for i in range(9):

%o m[i+1] += m[i] # _Chai Wah Wu_, Jan 24 2016

%Y Cf. A053108, A081139, A173000, A173187, A173188, A173191, A173192

%K nonn,easy

%O 0,2

%A _Vincenzo Librandi_, Oct 13 2011

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Last modified August 19 11:04 EDT 2024. Contains 375284 sequences. (Running on oeis4.)