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 A146977 a(n) = Sum_{k=1..prime(n)} binomial(2k,k). 3

%I

%S 8,28,350,4706,956384,14061140,3143981870,47564380970,11061198475550,

%T 40328534467494098,624021469287616610,2338958497948612884092,

%U 568740383597968804344752,8885203954833615367662872,2175457720411301277807088352,8390179243143767727343229863076

%N a(n) = Sum_{k=1..prime(n)} binomial(2k,k).

%H G. C. Greubel, <a href="/A146977/b146977.txt">Table of n, a(n) for n = 1..250</a>

%p seq( add(binomial(2*k,k), k=1..ithprime(n)), n=1..15); # _G. C. Greubel_, Jan 09 2020

%t Table[Sum[Binomial[2k,k],{k,Prime[n]}],{n,15}] (* _Harvey P. Dale_, Dec 31 2012 *)

%o (PARI) vector(15, n, sum(k=1,prime(n), binomial(2*k,k)) ) \\ _G. C. Greubel_, Jan 09 2020

%o (Magma) [ &+[Binomial(2*k,k): k in [1..NthPrime(n)]]: n in [1..15]]; // _G. C. Greubel_, Jan 09 2020

%o (Sage) [sum(binomial(2*k,k) for k in (1..nth_prime(n))) for n in (1..15)] # _G. C. Greubel_, Jan 09 2020

%Y A subsequence of A066796.

%K nonn

%O 1,1

%A _N. J. A. Sloane_, Apr 25 2009

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Last modified March 30 04:12 EDT 2023. Contains 361603 sequences. (Running on oeis4.)