A352553 a(n) = number of modules with n elements over the ring of integers in the real quadratic field of discriminant 13.

1, 0, 2, 1, 0, 0, 0, 0, 5, 0, 0, 2, 1, 0, 0, 2, 2, 0, 0, 0, 0, 0, 2, 0, 1, 0, 10, 0, 2, 0, 0, 0, 0, 0, 0, 5, 0, 0, 2, 0, 0, 0, 2, 0, 0, 0, 0, 4, 1, 0, 4, 1, 2, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 3, 0, 0, 0, 2, 4, 0, 0, 0, 0, 0, 2, 0, 0, 0, 2, 0, 20, 0, 0, 0, 0, 0, 4, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 1, 2, 0, 2, 0, 0, 0, 2, 10, 0, 0, 0, 0, 2, 0, 0, 2

Offset

1,3

Comments

See A352550 for comments and PARI code.

Links

Andrew Howroyd, Table of n, a(n) for n = 1..10000

R. Israel and D. Craddock, Are these sequences multiplicative?, Mathematics StackExchange, Oct 2025.

Crossrefs

Cf. A038540, A038541, A248107, A352550-A352567.

Sequence in context: A037874 A343870 A339070 * A077655 A117886 A145723

Adjacent sequences: A352550 A352551 A352552 * A352554 A352555 A352556

Keyword

nonn,mult

Author

N. J. A. Sloane, Mar 20 2022

Status

approved