A331152 - OEIS

%I #10 Dec 02 2020 07:40:03

%S 1,1,4,1,2,9,1,2,4,16,1,2,2,5,25,1,2,2,4,9,36,1,2,2,2,5,11,49,1,2,2,2,

%T 4,6,16,64,1,2,2,2,2,5,9,18,81,1,2,2,2,2,4,5,10,25,100,1,2,2,2,2,2,5,

%U 6,11,28,121,1,2,2,2,2,2,4,5,9,16,36,144,1,2,2,2,2,2,2,5,6,10,18,39,169

%N Triangle read by rows: T(n,k) (n>=k>=1) = f(n,n-k+1) where f(n,k) = ceiling((n/k)*floor(n/k)).

%H Robert J. McEliece and Herbert Taylor, <a href="https://doi.org/10.1016/0097-3165(73)90069-1">Covering tori with squares</a>, Journal of Combinatorial Theory, Series A 14.1 (1973): 119-124.

%e Triangle begins:

%e 1,

%e 1, 4,

%e 1, 2, 9,

%e 1, 2, 4, 16,

%e 1, 2, 2, 5, 25,

%e 1, 2, 2, 4, 9, 36,

%e 1, 2, 2, 2, 5, 11, 49,

%e 1, 2, 2, 2, 4, 6, 16, 64,

%e 1, 2, 2, 2, 2, 5, 9, 18, 81,

%e 1, 2, 2, 2, 2, 4, 5, 10, 25, 100,

%e 1, 2, 2, 2, 2, 2, 5, 6, 11, 28, 121,

%e 1, 2, 2, 2, 2, 2, 4, 5, 9, 16, 36, 144,

%e 1, 2, 2, 2, 2, 2, 2, 5, 6, 10, 18, 39, 169,

%e ...

%Y Cf. A331145-A331154.

%K nonn,tabl

%O 1,3

%A _N. J. A. Sloane_, Jan 14 2020