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 A060649 Smallest number k==3 (mod 4) such that Q(sqrt(-k)) has class number n. 1

%I

%S 3,15,23,39,47,87,71,95,199,119,167,231,191,215,239,399,383,335,311,

%T 455,431,591,647,695,479,551,983,831,887,671,719,791,839,1079,1031,

%U 959,1487,1199,1439,1271,1151,1959,1847,1391,1319,2615,3023,1751,1511,1799

%N Smallest number k==3 (mod 4) such that Q(sqrt(-k)) has class number n.

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/ClassNumber.html">Class Number.</a>

%t (* First do <<NumberTheory`NumberTheoryFunctions` *) a=Table[0, {50}]; Do[If[SquareFreeQ[n], c=ClassNumber[ -n]; If[c<=50&&a[[c]]==0, a[[c]]=n]], {n, 3, 3200, 4}]; a

%Y Cf. A002148, A081319.

%K nonn

%O 1,1

%A _Robert G. Wilson v_, Apr 17 2001

%E Edited by _Dean Hickerson_, Mar 17 2003

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Last modified December 9 22:27 EST 2019. Contains 329880 sequences. (Running on oeis4.)