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A218980 Integers not in A218852. 2
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, 71, 72, 79, 83, 89, 97, 101, 107, 113, 120, 127, 131, 137, 144, 149, 157, 163, 167, 173, 179, 180, 191, 197, 210, 211, 223, 227, 233, 239, 240, 251, 257, 263, 269, 277 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Conjecture: This sequence is infinite.

LINKS

Table of n, a(n) for n=1..60.

PROG

(JavaScript)

function divisorSum(n) {

c=0;

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

return c;

}

ds=new Array();

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

a=new Array();

ac=0;

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

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

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

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

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

i=0;

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

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

document.writeln(a);

b=new Array();

ac=0;

bc=0;

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

document.writeln(b);

CROSSREFS

Cf. A218852.

Sequence in context: A282697 A002479 A010458 * A084829 A018649 A341159

Adjacent sequences:  A218977 A218978 A218979 * A218981 A218982 A218983

KEYWORD

nonn

AUTHOR

Jon Perry, Nov 08 2012

STATUS

approved

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Last modified June 12 10:58 EDT 2021. Contains 344947 sequences. (Running on oeis4.)