A165993 - OEIS

%I #11 Aug 10 2014 14:05:28

%S 0,1,4,11,31,44,80,103,157,252,293,420,520,575,695,884,1105,1180,1431,

%T 1617,1704,2007,2217,2552,3040,3300,3439,3713,3852,4144,5255,5595,

%U 6120,6305,7252,7457,8060,8695,9141,9804,10507,10740,11983,12224,12740

%N a(n) = sum_{j=1..prime(n)-1} floor (j^2/prime(n)).

%H C. H. Gribble, <a href="/A165993/b165993.txt">Table of n, a(n) for n=1..78498 (i.e. for primes < 10^6)</a>.

%F a(n) = A166375(prime(n)-1). - _Charles R Greathouse IV_, Jun 28 2013

%t Table[Sum[Floor[j^2/n],{j,n-1}],{n,Prime[Range[50]]}] (* _Harvey P. Dale_, Aug 10 2014 *)

%o (PARI) a(n) = sum(j=1, prime(n)-1, floor (j^2/prime(n))) \\ _Michel Marcus_, Jun 20 2013

%o (PARI) a(n)=my(p=prime(n));sum(j=1,p-1,j^2\p) \\ _Charles R Greathouse IV_, Jun 20 2013

%Y Cf. A166375, A165974, A014817.

%K nonn

%O 1,3

%A _Christopher Hunt Gribble_, Oct 03 2009

%E Definition rephrased by R. J. Mathar, Oct 09 2009