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A081363 Smallest squarefree integer k such that Q(sqrt(k)) has class number n. 3
2, 10, 79, 82, 401, 235, 577, 226, 1129, 1111, 1297, 730, 4759, 1534, 9871, 2305, 7054, 4954, 15409, 3601, 7057, 4762, 23593, 9634, 24859, 13321, 8761, 5626, 49281, 11665, 97753, 15130, 55339, 19882, 25601, 18226, 24337, 19834, 41614, 16899, 55966, 47959 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

What is known about the asymptotics of this sequence? - Charles R Greathouse IV, Jan 26 2017

Records: 2, 10, 79, 82, 401, 577, 1129, 1297, 4759, 9871, 15409, 23593, 24859, 49281, 97753, 106537, 159199, 197137, 212137, 239119, 245023, 444089, 589822, 614849, 815413, 837929, 943951, 1025494, 1224121, 1240369, 1333255, 1334026, ..., . - Robert G. Wilson v, Apr 12 2017

LINKS

Robert G. Wilson v, Table of n, a(n) for n = 1..214

MATHEMATICA

t[_] := 0; k = 2; While[k < 56000, cn = NumberFieldClassNumber@Sqrt@k; If[ t[cn] == 0, t[cn] = k; Print[{cn, k}]]; k++]; t@# & /@ Range@ 42 (* Robert G. Wilson v, Apr 12 2017 *)

PROG

(PARI) v=vector(100); for(n=2, 1e6, if(!issquarefree(n), next); t=qfbclassno(if(n%4>1, 4*n, n)); if(t<=#v && v[t]==0, v[t]=n; print("a("t") = "n))) \\ Charles R Greathouse IV, Jan 26 2017

CROSSREFS

Cf. A081319, A081364, A094619, A094612, A094613, A094614.

Cf. A219361, A029702, A029703, A029704, A029705, A218038, A218039, A218040, A218041, A218042, A276541. - Robert G. Wilson v, Apr 12 2017

Sequence in context: A052568 A063170 A098636 * A279908 A245903 A100248

Adjacent sequences:  A081360 A081361 A081362 * A081364 A081365 A081366

KEYWORD

nonn

AUTHOR

Dean Hickerson, Mar 19 2003

EXTENSIONS

More terms from Max Alekseyev, Apr 28 2010

STATUS

approved

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Last modified May 24 07:19 EDT 2017. Contains 286939 sequences.