cp's OEIS Frontend

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.

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A379424 Least modulus k such that the multiplicative group modulo k has a difference of n nontrivial cycles between its minimal and maximal representation.

Original entry on oeis.org

1, 7, 31, 211, 1333, 6541, 45787, 281263, 1968841, 13781887, 93098053, 649998793, 4549991551, 31849940857, 215149600483, 1506047203381, 10542330423667, 86982188480467, 587573558919073, 4113014912433511, 28791104387034577, 247368468304929733
Offset: 0

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Author

Asher Gray, Dec 22 2024

Keywords

Comments

This is equal to the least modulus k such that (Z/kZ)* has a representation as a direct product of cyclic groups, of which n are odd cycles. The number of even cycles in the maximal representation is equal to the total cycles in the minimal representation.

Examples

			a(4) = 1333 because (Z/1333Z) ≅ C210 x C6 ≅ C2 x C3 x C5 x C2 x C3 x C7. The first representation has 2 cycles and the second has 6, a difference of 4.
		

Crossrefs

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