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A038541 a(n) = number of modules with n elements over the ring of integers in the imaginary quadratic field of discriminant -20. 20
1, 1, 2, 2, 1, 2, 2, 3, 5, 1, 0, 4, 0, 2, 2, 5, 0, 5, 0, 2, 4, 0, 2, 6, 2, 0, 10, 4, 2, 2, 0, 7, 0, 0, 2, 10, 0, 0, 0, 3, 2, 4, 2, 0, 5, 2, 2, 10, 5, 2, 0, 0, 0, 10, 0, 6, 0, 2, 0, 4, 2, 0, 10, 11, 0, 0, 2, 0, 4, 2, 0, 15, 0, 0, 4, 0, 0, 0, 0, 5, 20, 2, 2, 8, 0, 2, 4, 0, 2, 5, 0, 4, 0, 2, 0, 14 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,3
COMMENTS
Equivalently, number of modules with n elements over the ring Z[sqrt(-5)].
See A352550 for comments and PARI code.
LINKS
CROSSREFS
Sequence in context: A226983 A112175 A112206 * A070215 A071457 A227782
KEYWORD
nonn,mult
AUTHOR
Paolo Dominici (pl.dm(AT)libero.it)
EXTENSIONS
Edited by M. F. Hasler, Feb 18 2022
Revised by N. J. A. Sloane, Mar 21 2022
STATUS
approved

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Last modified August 21 17:22 EDT 2024. Contains 375353 sequences. (Running on oeis4.)