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A131381 a(n) = binomial(2*n,n) mod (n+2), with n>=1. 1

%I #15 Sep 22 2021 17:22:58

%S 2,2,0,4,0,4,3,0,0,4,0,0,5,8,0,0,0,0,0,0,0,0,0,0,9,0,0,10,0,16,11,0,0,

%T 24,0,0,26,0,0,28,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,32,0,0,0,

%U 0,0,0,0,0,0,0,0,0,0,0,0,0,27,0,0,28,0,0,29,0,0,60,0,0,62,0,0,64,0,0,0,0

%N a(n) = binomial(2*n,n) mod (n+2), with n>=1.

%C Contains large zones of zeros.

%H Michael De Vlieger, <a href="/A131381/b131381.txt">Table of n, a(n) for n = 0..9999</a>

%e n=6 -> binomial(12,6) mod 8 -> 12!/(6!*6!) mod 8 -> 924 mod 8 -> 4.

%p P:=proc(n) local i,j; for i from 1 by 1 to n do j:=(binomial(2*i,i) mod (i+2)); print(j); od; end: P(200);

%t Table[Mod[Binomial[2n,n],n+2],{n,100}] (* _Harvey P. Dale_, Aug 23 2011 *)

%Y Cf. A118114, A131382.

%K easy,nonn

%O 0,1

%A _Paolo P. Lava_ and _Giorgio Balzarotti_, Jul 05 2007

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Last modified April 23 20:33 EDT 2024. Contains 371916 sequences. (Running on oeis4.)