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A118013 Triangle read by rows: T(n,k) = floor(n^2/k), 1<=k<=n. 10

%I

%S 1,4,2,9,4,3,16,8,5,4,25,12,8,6,5,36,18,12,9,7,6,49,24,16,12,9,8,7,64,

%T 32,21,16,12,10,9,8,81,40,27,20,16,13,11,10,9,100,50,33,25,20,16,14,

%U 12,11,10,121,60,40,30,24,20,17,15,13,12,11,144,72,48,36,28,24,20,18,16,14

%N Triangle read by rows: T(n,k) = floor(n^2/k), 1<=k<=n.

%C T(n,1) = A000290(n); T(n,n) = n;

%C T(n,2) = A007590(n) for n>1;

%C T(n,3) = A000212(n) for n>2;

%C T(n,4) = A002620(n) for n>3;

%C T(n,5) = A118015(n) for n>4;

%C T(n,6) = A056827(n) for n>5;

%C central terms give A008574: T(2*k-1,k) = 4*(k-1)+0^(k-1);

%C row sums give A118014.

%H Reinhard Zumkeller, <a href="/A118013/b118013.txt">Rows n=1..100 of triangle, flattened</a>

%e Triangle begins:

%e 1,

%e 4, 2,

%e 9, 4, 3,

%e 16, 8, 5, 4,

%o (PARI) T(n,k)=n^2\k \\ _Charles R Greathouse IV_, Jan 15 2012

%o (Haskell)

%o a118013 n k = a118013_tabl !! (n-1) !! (k-1)

%o a118013_row n = map (div (n^2)) [1..n]

%o a118013_tabl = map a118013_row [1..]

%o -- _Reinhard Zumkeller_, Jan 22 2012

%Y Cf. A010766.

%K nonn,easy,tabl

%O 1,2

%A _Reinhard Zumkeller_, Apr 10 2006

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Last modified September 20 07:21 EDT 2020. Contains 337264 sequences. (Running on oeis4.)