A344408 Positive discriminants of orders with class number 2.

40, 60, 65, 85, 96, 104, 105, 120, 136, 140, 156, 160, 165, 168, 185, 192, 200, 204, 205, 220, 221, 224, 232, 240, 252, 260, 264, 265, 273, 280, 285, 288, 296, 300, 305, 312, 320, 325, 336, 340, 345, 348, 352, 357, 360, 364, 365, 377, 380, 384, 385, 408

Offset

1,1

Comments

Also positive discriminants of orders with class group isomorphic to C_2.

The fundamental terms are listed in A094619.

Links

Jianing Song, Table of n, a(n) for n = 1..10001

Prog

(PARI) isA344408(d) = (d>0) && !issquare(d) && ((d%4==0)||(d%4==1)) && quadclassunit(d)[2]==[2]

Crossrefs

Cf. A133315 (positive discriminants of orders with class number 1), this sequence (class number 2), A344409 (class number 3).

Cf. A322710 (the negative discriminant case), A094619.

Sequence in context: A126816 A361623 A259061 * A035120 A094619 A052475

Adjacent sequences: A344405 A344406 A344407 * A344409 A344410 A344411

Keyword

nonn

Author

Jianing Song, May 17 2021

Status

approved