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Search: id:A145769
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| A145769 |
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Numbers n such that the number of positive divisors of n and the sum of the positive divisors of n are both square numbers. |
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+0
1
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| 1, 22, 94, 115, 119, 210, 214, 217, 265, 343, 382, 497, 510, 517, 527, 679, 745, 862, 889, 930, 966, 1155, 1174, 1177, 1207, 1219, 1393, 1416, 1465, 1501, 1566, 1624, 1649, 1672, 1687, 1915, 1942, 2101, 2130, 2159, 2201, 2226, 2346, 2359, 2530, 2618
(list; graph; listen)
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OFFSET
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1,2
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COMMENT
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These might be called square sublime numbers.
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EXAMPLE
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Number of divisors of 94 is 4 = 2^2, sum of divisors of 94 is 144 = 12^2. Hence 94 is in the sequence. [From Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), Oct 21 2008]
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CROSSREFS
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Cf. A023194.
Cf. A000005 (number of divisors), A000203 (sum of divisors), A000290 (squares). [From Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), Oct 21 2008]
Sequence in context: A041942 A041944 A144934 this_sequence A159539 A026909 A060382
Adjacent sequences: A145766 A145767 A145768 this_sequence A145770 A145771 A145772
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KEYWORD
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nonn
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AUTHOR
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Howard Berman (howard_berman(AT)hotmail.com), Oct 18 2008
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EXTENSIONS
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Extended by Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), Oct 21 2008
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