A051994 -id:A051994 - cp's OEIS frontend

A051990 Discriminants of real quadratic fields of ERD-type with class groups of exponent 2 and discriminants of the form D = r^2*k^2+k, k odd.

10, 15, 26, 30, 35, 39, 42, 65, 78, 95, 105, 110, 122, 143, 170, 182, 195, 203, 210, 222, 230, 255, 290, 327, 362, 395, 462, 483, 485, 530, 663, 885, 903, 915, 930, 962, 1155, 1157, 1173, 1190, 1218, 1230, 1295, 1370, 1463, 1482, 1518, 1595

Offset: 1

N. J. A. Sloane, Jan 04 2000

R. A. Mollin, Quadratics, CRC Press, 1996, Appendix A, Table A4(1), column D.

Georg Fischer, Table of n, a(n) for n = 1..98

Cf. A051991, A051992, A051993, A051994, A051995, A051996, A051997, A051998.

A051991 Discriminants of real quadratic fields of ERD-type with class groups of exponent 2 and discriminants of the form D = r^2*k^2+2k, k odd.

Original entry on oeis.org

34, 51, 66, 87, 102, 119, 123, 138, 146, 194, 215, 231, 258, 287, 318, 330, 390, 402, 410, 435, 447, 455, 482, 527, 570, 615, 623, 627, 635, 678, 770, 782, 798, 843, 890, 902, 1022, 1095, 1235, 1298, 1302, 1515, 1547, 1610, 1770, 1938, 1995

Offset: 1

N. J. A. Sloane, Jan 04 2000

Excludes discriminants appearing in A051990.

R. A. Mollin, Quadratics, CRC Press, 1996, Appendix A, Table A4(2), column D.

Georg Fischer, Table of n, a(n) for n = 1..76

Cf. A051990, A051992, A051993, A051994, A051995, A051996, A051997, A051998.

A051992 Discriminants of real quadratic fields of ERD-type with class groups of exponent 2 and discriminants of the form D = r^2*k^2+4k, k odd.

Original entry on oeis.org

85, 165, 205, 221, 285, 357, 365, 429, 533, 629, 645, 741, 957, 965, 1085, 1205, 1245, 1365, 1469, 1517, 1533, 1685, 1853, 1965, 2013, 2037, 2045, 2085, 2373, 2397, 2405, 2613, 2805, 2813, 3005, 3045, 3237, 3485, 3885, 3965, 4245, 4277

Offset: 1

N. J. A. Sloane, Jan 04 2000

Excludes discriminants appearing in A051990.

R. A. Mollin, Quadratics, CRC Press, 1996, Appendix A, Table A4(3), column D.

Georg Fischer, Table of n, a(n) for n = 1..81

Cf. A051990, A051991, A051993, A051994, A051995, A051996, A051997, A051998.

A051993 Consider real quadratic fields of ERD-type with class groups of exponent 2 and discriminants of the form D = r^2*k^2+k, k odd; sequence gives values of r.

Original entry on oeis.org

3, 4, 5, 1, 6, 2, 1, 8, 3, 2, 2, 1, 11, 12, 13, 1, 14, 2, 1, 5, 3, 16, 17, 6, 19, 4, 1, 22, 22, 23, 2, 2, 10, 2, 1, 31, 34, 34, 2, 1, 5, 7, 36, 37, 2, 1, 13, 8, 8, 1, 14, 9, 2, 46, 47, 16, 3, 4, 56, 3, 2, 58, 20, 12, 2, 3, 2, 23, 10, 2, 24, 73, 5, 4, 2, 16, 2, 4, 8, 8, 19, 98, 20, 2, 2, 4, 24, 11, 122, 4, 4, 142, 26, 68, 242, 278, 22, 32

Offset: 1

N. J. A. Sloane, Jan 04 2000

R. A. Mollin, Quadratics, CRC Press, 1996, Appendix A, Table A4(1), column r.

Cf. A051990, A051991, A051992, A051994, A051995, A051996, A051997, A051998.

a(83) and following from Georg Fischer, Sep 21 2021

A051995 Consider real quadratic fields of ERD-type with class groups of exponent 2 and discriminants of the form D = r^2*k^2+4k, k odd; sequence gives values of r.

Original entry on oeis.org

9, 1, 3, 1, 1, 1, 19, 7, 23, 25, 5, 9, 1, 31, 1, 7, 7, 1, 3, 1, 13, 41, 43, 3, 15, 15, 9, 3, 7, 1, 49, 17, 1, 53, 11, 11, 19, 59, 3, 1, 13, 4, 1, 23, 5, 15, 7, 11, 27, 5, 5, 1, 3, 1, 7, 1, 19, 3, 101, 7, 3, 3, 11, 25, 127, 43, 7, 27, 13, 29, 3, 31, 3, 1, 25, 59, 179, 9, 7, 47, 13

Offset: 1

N. J. A. Sloane, Jan 04 2000

Excludes discriminants appearing in A051990.

R. A. Mollin, Quadratics, CRC Press, 1996, Appendix A, Table A4(3), column r.

Cf. A051990, A051991, A051992, A051993, A051994, A051996, A051997, A051998.

Offset changed to 1 by Georg Fischer, Sep 21 2021

A051996 Consider real quadratic fields of ERD-type with class groups of exponent 2 and discriminants of the form D = r^2*k^2+k, k odd; sequence gives values of k.

Original entry on oeis.org

1, -1, 1, 5, -1, 3, -7, 1, -3, -5, 5, -11, 1, -1, 1, 13, -1, 7, -15, -3, 5, -1, 1, 3, 1, -5, 21, -1, 1, 1, -13, -15, 3, 15, -31, 1, -1, 1, 17, -35, -7, 5, -1, 1, 19, -39, -3, -5, 5, 41, 3, 5, -23, 1, 1, -3, 17, 13, -1, -19, -29, 1, -3, 5, -31, 21, 33, -3, -7, 35, 3, 1, -15, -19, -39, 5, 41, -21, -11, 11, 5, 1, 5, -55, 55, 29, 5, -11, 1, -35, 35, 1, -7, -3, 1, 1, -15, 21

Offset: 1

N. J. A. Sloane, Jan 04 2000

R. A. Mollin, Quadratics, CRC Press, 1996, Appendix A, Table A4(1), column k.

Cf. A051990, A051991, A051992, A051993, A051994, A051995, A051997, A051998.

a(73) and following from Georg Fischer, Sep 21 2021

A051997 Consider real quadratic fields of ERD-type with class groups of exponent 2 and discriminants of the form D = r^2*k^2+2k, k odd; sequence gives values of k.

Original entry on oeis.org

-1, 1, 1, 3, 1, -1, 1, -3, 1, -1, -5, 3, 1, -1, -3, 3, -5, 1, 5, -3, 3, 7, -1, -1, -3, -5, -1, 1, 5, 1, -7, -1, 7, 1, -5, 1, -1, 3, 5, 1, 3, -3, 13, 5, 3, 1, -15, -5, 3, -7, 7, -3, 3, 13, -3, -11, 3, -15, 1, -1, -21, -33, 15, 3, -3, -5, 5, -17, 7, 3, 5, 1, -5, 7, 3, -13

Offset: 1

N. J. A. Sloane, Jan 04 2000

Excludes discriminants appearing in A051990.

R. A. Mollin, Quadratics, CRC Press, 1996, Appendix A, Table A4(2), column k.

Cf. A051990, A051991, A051992, A051993, A051994, A051995, A051996, A051998.

Offset changed to 1 by Georg Fischer, Sep 21 2021

A051998 Consider real quadratic fields of ERD-type with class groups of exponent 2 and discriminants of the form D = r^2*k^2+4k, k odd; sequence gives values of k.

Original entry on oeis.org

1, -15, -5, -17, -19, -21, 1, -3, 1, 1, 5, 3, -33, 1, -35, -5, 5, -39, -13, -41, 3, 1, 1, -15, -3, 3, 5, 15, -7, -51, 1, 3, -55, 1, -5, 5, -3, 1, -21, -65, 5, 13, -69, 3, -15, 5, -11, 7, 3, -17, 17, -89, 29, -91, 13, -95, -5, 33, 1, -15, 35, 39, 11, 5, 1, 3, 19, 5, -11, 5, -51, 5, 53, -165, -7, -3, 1, 21, -29, -5, 21

Offset: 1

N. J. A. Sloane, Jan 04 2000

Excludes discriminants appearing in A051990.

R. A. Mollin, Quadratics, CRC Press, 1996, Appendix A, Table A4(3), column k.

Cf. A051990, A051991, A051992, A051993, A051994, A051995, A051996, A051997.

a(69) and following from Georg Fischer, Sep 21 2021

cp's OEIS Frontend

A051990 Discriminants of real quadratic fields of ERD-type with class groups of exponent 2 and discriminants of the form D = r^2*k^2+k, k odd.

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A051991 Discriminants of real quadratic fields of ERD-type with class groups of exponent 2 and discriminants of the form D = r^2*k^2+2k, k odd.

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A051992 Discriminants of real quadratic fields of ERD-type with class groups of exponent 2 and discriminants of the form D = r^2*k^2+4k, k odd.

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A051993 Consider real quadratic fields of ERD-type with class groups of exponent 2 and discriminants of the form D = r^2*k^2+k, k odd; sequence gives values of r.

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A051995 Consider real quadratic fields of ERD-type with class groups of exponent 2 and discriminants of the form D = r^2*k^2+4k, k odd; sequence gives values of r.

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A051996 Consider real quadratic fields of ERD-type with class groups of exponent 2 and discriminants of the form D = r^2*k^2+k, k odd; sequence gives values of k.

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A051997 Consider real quadratic fields of ERD-type with class groups of exponent 2 and discriminants of the form D = r^2*k^2+2k, k odd; sequence gives values of k.

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A051998 Consider real quadratic fields of ERD-type with class groups of exponent 2 and discriminants of the form D = r^2*k^2+4k, k odd; sequence gives values of k.

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