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This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A239661 Divisors of 1089.

Original entry on oeis.org

1, 3, 9, 11, 33, 99, 121, 363, 1089
Offset: 1

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Author

Omar E. Pol, Jun 10 2014

Keywords

Comments

Divisors of 33^2.
The sum of divisors of 1089 is equal to 1729, the Hardy-Ramanujan number: A000203(1089) = A001235(1) = 1729.
The aliquot divisors of 1089 are also the powers of 3 written in base 26, see A004668.
Also 1089 is widely used in magic tricks because it can be produced from any two three-digit numbers (see Links section).

Examples

			Sigma(1089) = 1 + 3 + 9 + 11 + 33 + 99 + 121 + 363 + 1089 = 1729.

Links

Crossrefs

Cf. A000203, A001235, A004668.

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