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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.

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A374001 a(n) is the number of elements z of Z_p[i] such that #{z^k, k >= 0} = p^2-1 (where p denotes A002145(n), the n-th prime number congruent to 3 modulo 4).

Original entry on oeis.org

4, 16, 32, 96, 160, 256, 480, 704, 896, 1280, 1152, 1536, 1920, 3072, 3744, 4608, 3840, 4224, 5760, 8640, 7872, 8448, 9216, 9600, 9984, 13824, 16128, 12288, 14400, 20800, 18432, 25760, 23040, 23040, 26240, 38528, 34176, 42240, 31104, 48640, 34560, 48384, 46080
Offset: 1

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Author

Rémy Sigrist, Jun 24 2024

Keywords

Comments

Z_p[i] is a field iff p is a prime number congruent to 3 modulo 4.
a(n) is the number of generators of the multiplicative group Z_p[i] \ {0} (where p denotes A002145(n)).

Examples

			For n = 2:
- the second prime number congruent to 3 modulo 4 is p = 7,
- the number of elements of {(x + i*y)^k, k >= 0} where x and y belong to Z_7 are:
  x\y | 0   1   2   3   4   5   6
  ----+--------------------------
    0 | 2   4  12  12  12  12   4
    1 | 1  24  48  48  48  48  24
    2 | 3  48   8  16  16   8  48
    3 | 6  48  16  24  24  16  48
    4 | 3  48  16  24  24  16  48
    5 | 6  48   8  16  16   8  48
    6 | 2  24  48  48  48  48  24
- the number 48 appears 16 times, so a(2) = 16.
		

Crossrefs

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