A390526 Norms of irreducible elements of Z[sqrt(10)].

4, 6, 9, 10, 15, 25, 26, 31, 39, 41, 49, 65, 71, 74, 79, 86, 89, 106, 111, 121, 129, 134, 151, 159, 166, 169, 185, 191, 199, 201, 214, 215, 239, 241, 249, 265, 271, 281, 289, 311, 314, 321, 326, 335, 346, 359, 361, 394, 401, 409, 415, 431, 439, 449, 454, 471, 479, 481, 489

Offset

1,1

Comments

Note that Q(sqrt(10)) has class number 2.

A391362 is the main sequence.

Links

Jianing Song, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A097955 (primes decomposing in Q(sqrt(10))), A038880 (primes remaining inert in Q(sqrt(10))), A141180 ((p) is the product of two principal ideals), A141179 ((p) is the product of two non-principal ideals).

Other sequences related to factorizations in Z[sqrt(10)]: A391367, A391362, A262362.

Analogs in other quadratic fields with class number 2: A390422 (discriminant -15), A091730 (discriminant -20), A390498 (discriminant -24).

Sequence in context: A111206 A087112 A077554 * A382901 A262812 A287296

Adjacent sequences: A390523 A390524 A390525 * A390527 A390528 A390529

Keyword

nonn,easy

Author

Jianing Song, Dec 07 2025

Status

approved