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 A183862 a(n) = n + floor(sqrt(5*n/2)); complement of A183863. 1

%I

%S 2,4,5,7,8,9,11,12,13,15,16,17,18,19,21,22,23,24,25,27,28,29,30,31,32,

%T 34,35,36,37,38,39,40,42,43,44,45,46,47,48,50,51,52,53,54,55,56,57,58,

%U 60,61,62,63,64,65,66,67,68,70,71,72,73,74,75,76,77,78,79,81,82,83,84,85,86,87,88,89,90,91,93,94

%N a(n) = n + floor(sqrt(5*n/2)); complement of A183863.

%C Also n + floor(sqrt(5*n/2 + 1/2)) since 5*n/2 + 1/2 is never a square. - _Charles R Greathouse IV_, Feb 11 2011

%t a=5/2; b=1/2;

%t Table[n+Floor[(a*n+b)^(1/2)],{n,80}]

%t Table[n-1+Ceiling[(n*n-b)/a],{n,70}]

%o (PARI) a(n)=n+sqrtint(5*n/2)

%Y Cf. A183863.

%K nonn,easy

%O 1,1

%A _Clark Kimberling_, Jan 07 2011

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Last modified November 27 14:41 EST 2022. Contains 358405 sequences. (Running on oeis4.)