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A046870
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Sigma[ 1,n ] divides Sigma[ 4,n ].
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1
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1, 4, 9, 16, 20, 25, 36, 49, 50, 64, 81, 100, 117, 121, 144, 169, 180, 196, 225, 242, 256, 289, 324, 325, 361, 400, 441, 450, 468, 484, 500, 529, 576, 578, 605, 625, 650, 676, 729, 784, 800, 841, 900, 961, 980, 1024, 1025, 1058, 1089, 1156, 1225, 1280, 1296
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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COMMENTS
| sigma_1(n) is the sum of the divisors of n [same as sigma(n)] (A000203).
sigma_2(n) is the sum of the squares of the divisors of n (A001157).
sigma_4(n) is the sum of the 4th powers of the divisors of n (A001159).
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EXAMPLE
| n=a[ 18 ]=196 of which divisor power sums for k=0,1,2,3,4 are 9,399,51471, 8613489, 1574446419. Sigma_1=399 and Sigma_4=51471*30589=399*129*30589. Thus Both Sigma_2 and Sigma_1 divide Sigma_4.
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CROSSREFS
| Has large overlap with A020487.
Sequence in context: A010441 A046871 A020487 * A127702 A010461 A010421
Adjacent sequences: A046867 A046868 A046869 * A046871 A046872 A046873
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KEYWORD
| nonn
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AUTHOR
| Labos E. (labos(AT)ana.sote.hu)
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