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Integers not in A218852.
2

%I #15 Nov 10 2012 14:34:03

%S 1,2,3,4,6,8,9,11,12,17,18,22,23,24,29,30,36,37,41,47,48,53,59,60,67,

%T 71,72,79,83,89,97,101,107,113,120,127,131,137,144,149,157,163,167,

%U 173,179,180,191,197,210,211,223,227,233,239,240,251,257,263,269,277

%N Integers not in A218852.

%C Conjecture: This sequence is infinite.

%o (JavaScript)

%o function divisorSum(n) {

%o c=0;

%o for (i=1;i<=n;i++) if (n%i==0) c+=i;

%o return c;

%o }

%o ds=new Array();

%o for (j=1;j<1001;j++) ds[j]=divisorSum(j);

%o a=new Array();

%o ac=0;

%o for (j=1;j<300;j++)

%o for (k=1;k<=j;k++)

%o for (m=1;m<=k;m++)

%o if (ds[j]+ds[k]+ds[m]==ds[j+k+m]) a[ac++]=j+k+m;

%o a.sort(function(a, b) {return a-b;});

%o i=0;

%o while(i++<a.length-1)

%o if (a[i]==a[i+1]) a.splice(i--,1);

%o document.writeln(a);

%o b=new Array();

%o ac=0;

%o bc=0;

%o for (i=0;i<a[a.length-1];i++) if (a[ac]!=i) b[bc++]=i; else ac++;

%o document.writeln(b);

%Y Cf. A218852.

%K nonn

%O 1,2

%A _Jon Perry_, Nov 08 2012