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A216995
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Multiples of 11 whose digit sum is a multiple of 11.
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10
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209, 308, 407, 506, 605, 704, 803, 902, 2090, 2299, 2398, 2497, 2596, 2695, 2794, 2893, 2992, 3080, 3289, 3388, 3487, 3586, 3685, 3784, 3883, 3982, 4070, 4279, 4378, 4477, 4576, 4675, 4774, 4873, 4972, 5060, 5269, 5368, 5467, 5566, 5665, 5764, 5863, 5962, 6050
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refs;
listen;
history;
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OFFSET
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1,1
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COMMENTS
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Nothing between 1000 and 2000.
Also, there are no a(n) from 10902 to 12198 (this interval contains 117 multiples of 11). [Bruno Berselli, Oct 26 2012]
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LINKS
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EXAMPLE
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3487 = 11*317 and 3+4+8+7 = 22 = 11*2.
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MATHEMATICA
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Select[11*Range[1000], Mod[Total[IntegerDigits[#]], 11] == 0 &] (* T. D. Noe, Sep 24 2012 *)
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PROG
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(JavaScript)
function sumarray(arr) {
t=0;
for (i=0; i<arr.length; i++) t+=arr[i];
return t;
}
k=11;
for(s=1; s<1000; s++) {
a=new Array();
x=(s*k).toString();
for (j=0; j<x.length; j++) a[j]=Number(x.charAt(j));
if (sumarray(a)%k==0) document.write(s*k+", ");
}
(Python)
def sd(n): return sum(map(int, str(n)))
def ok(n): return n%11 == 0 and sd(n)%11 == 0
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CROSSREFS
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KEYWORD
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nonn,base
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AUTHOR
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STATUS
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approved
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