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 A026079 a(n) = Sum_{k = 1..n} T(k,k-1), where T is the array defined in A024996. 1

%I #12 May 22 2017 07:51:57

%S 1,3,6,12,31,83,233,661,1893,5445,15720,45510,132069,384049,1118822,

%T 3264644,9539789,27913085,81769238,239794424,703906721,2068153901,

%U 6081507833,17896695833,52703944967,155310270103,457956633828,1351132539606,3988457429607

%N a(n) = Sum_{k = 1..n} T(k,k-1), where T is the array defined in A024996.

%H G. C. Greubel, <a href="/A026079/b026079.txt">Table of n, a(n) for n = 1..1000</a>

%F a(n) = A025179(n) + 2, n>2.

%t Join[{1, 3}, Table[Sum[ Binomial[n, 2*k]*Binomial[2*k + 1, k + 1], {k, 0, Floor[n/2]}] + 2, {n,2,50}]] (* _G. C. Greubel_, May 22 2017 *)

%o (PARI) concat([1,3], for(n=2,50, print1(2 + sum(k=0,floor(n/2), binomial(n, 2*k)*binomial(2*k+1, k+1)), ", "))) \\ _G. C. Greubel_, May 22 2017

%Y Cf. A025179.

%K nonn

%O 1,2

%A _Clark Kimberling_

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Last modified August 13 20:02 EDT 2024. Contains 375144 sequences. (Running on oeis4.)