A174428 - OEIS

%I #10 Apr 17 2014 11:25:54

%S 0,0,1,0,0,1,0,1,1,3,0,0,0,2,1,0,0,0,0,2,0,0,0,2,0,3,2,1,0,1,0,3,0,3,

%T 1,7,0,1,1,1,3,1,6,5,4,0,0,0,2,3,0,4,2,0,8,0,0,0,0,2,0,5,4,3,2,1,0,0,

%U 1,0,3,4,0,4,1,8,6,4,0,0,2,2,4,2,0,6,5,4,3,2,1,0,0,0,0,4,0,3,0,6,4,2,0,11,10

%N Triangle read by rows: R(n,k)= sigma(n) mod k, where sigma(.) is the sum of divisors.

%e The triangle starts in row n=1 with columns 1<=k<=n as:

%e 0;

%e 0,1;

%e 0,0,1;

%e 0,1,1,3;

%e 0,0,0,2,1;

%e 0,0,0,0,2,0;

%e 0,0,2,0,3,2,1;

%t Flatten[Table[Mod[DivisorSigma[1,n],k],{n,20},{k,n}]] (* _Harvey P. Dale_, Apr 17 2014 *)

%Y Cf. A000203, A154234.

%K nonn,tabl

%O 1,10

%A _Juri-Stepan Gerasimov_, Nov 28 2010