A390498 - OEIS

%I #29 Dec 27 2025 15:51:51

%S 4,6,7,9,10,15,22,25,31,33,55,58,73,79,87,97,103,106,118,121,127,145,

%T 151,159,166,169,177,193,199,202,214,223,241,249,262,265,271,289,295,

%U 298,303,313,319,321,337,346,358,361,367,393,394,409,415,433,439,447,454,457,463,487

%N Norms of irreducible elements of Z[sqrt(-6)].

%C Note that Q(sqrt(-6)) has class number 2.

%C A391361 is the main sequence.

%H Jianing Song, <a href="/A390498/b390498.txt">Table of n, a(n) for n = 1..10000</a>

%Y Cf. A157437 (primes decomposing in Q(sqrt(-6))), A191059 (prime remaining inert in Q(sqrt(-6))), A033199 ((p) is the product of two principal ideals), A084865 ((p) is the product of two non-principal ideals).

%Y Other sequences related to factorizations in Z[sqrt(-6)]: A391366, A391361, A391364.

%Y Analogs in other quadratic fields with class number 2: A390422 (discriminant -15), A091730 (discriminant -20), A390526 (discriminant 40).

%K nonn,easy

%O 1,1

%A _Jianing Song_, Dec 07 2025