cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-4 of 4 results.

A102269 Primes p such that Q(sqrt(-21p)) has genus characters chi_{-3} = +1, chi_{-7} = +1.

Original entry on oeis.org

43, 67, 79, 127, 151, 163, 211, 331, 379, 463, 487, 499, 547, 571, 631, 739, 751, 823, 883, 907, 919, 967, 991, 1051, 1087, 1171, 1303, 1327, 1423, 1471, 1579, 1663, 1723, 1747, 1759, 1831, 1999, 2011, 2083, 2143, 2179, 2251, 2311, 2347, 2503, 2647, 2671, 2683, 2731, 2767, 2851, 3019
Offset: 1

Views

Author

N. J. A. Sloane, Feb 19 2005

Keywords

Comments

Primes p such that p is 3 (mod 4) and (-3/p) = (-7/p) = 1, where (k/n) is the Kronecker symbol. - Robin Visser, Mar 13 2024

Crossrefs

Programs

  • Magma
    [p : p in PrimesUpTo(3000) | p mod 84 in [43, 67, 79]];  // Robin Visser, Mar 13 2024

Formula

The primes are congruent to {43, 67, 79} (mod 84). - Robin Visser, Mar 13 2024

Extensions

More terms from Robin Visser, Mar 13 2024

A102275 2-class number of Q(sqrt(-21p)) as p runs through primes in A102274.

Original entry on oeis.org

8, 32, 8, 8, 8, 32, 64, 8, 16, 16, 64, 8, 16, 16, 16, 8, 32, 8, 8, 8, 32, 8, 16, 8, 8, 8, 8, 8, 32, 16, 8, 16, 128, 32, 32, 8, 32, 16, 32, 8, 128, 16, 16, 16, 8, 8, 16, 8, 16, 8, 8, 8, 16, 16, 16, 8, 64, 8, 8, 16, 8, 8, 8, 8, 8, 8, 8, 16, 16, 16, 32, 16, 8, 16, 32, 16, 8, 8, 32, 16, 16
Offset: 1

Views

Author

N. J. A. Sloane, Feb 19 2005

Keywords

Crossrefs

Programs

  • Sage
    [2^QuadraticField(-21*p).class_number().valuation(2) for p in Primes()[:1000] if (p%84) in [47, 59, 83]] # Robin Visser, Mar 13 2024

Extensions

a(19) corrected and more terms from Robin Visser, Mar 13 2024

A102270 2-class number of Q(sqrt(-21p)) as p runs through primes in A102269.

Original entry on oeis.org

16, 8, 8, 8, 16, 8, 16, 16, 16, 8, 16, 32, 8, 8, 8, 8, 32, 8, 16, 64, 32, 8, 32, 8, 8, 128, 32, 32, 32, 16, 8, 8, 8, 16, 16, 8, 8, 8, 128, 16, 8, 8, 16, 32, 8, 16, 32, 8, 8, 8, 128, 8, 8, 8, 16, 8, 64, 8, 8, 8, 16, 8, 16, 16, 16, 8, 8, 16, 32, 16, 8, 8, 8, 64, 32, 64, 16, 64, 8, 16, 32
Offset: 1

Views

Author

N. J. A. Sloane, Feb 19 2005

Keywords

Crossrefs

Programs

  • Sage
    [2^QuadraticField(-21*p).class_number().valuation(2) for p in Primes()[:1000] if (p%84) in [43, 67, 79]] # Robin Visser, Mar 13 2024

Extensions

More terms from Robin Visser, Mar 13 2024

A102274 Primes p such that Q(sqrt(-21p)) has genus characters chi_{-3} = -1, chi_{-7} = -1.

Original entry on oeis.org

47, 59, 83, 131, 167, 227, 251, 311, 383, 419, 467, 479, 503, 563, 587, 647, 719, 839, 887, 971, 983, 1091, 1151, 1223, 1259, 1307, 1319, 1427, 1487, 1511, 1559, 1571, 1811, 1823, 1847, 1907, 1931, 1979, 2063, 2099, 2243, 2267, 2351, 2399, 2411, 2579, 2663, 2687, 2819, 2903, 2939, 2999
Offset: 1

Views

Author

N. J. A. Sloane Feb 19 2005

Keywords

Comments

Primes p such that p is 3 (mod 4) and (-3/p) = (-7/p) = -1, where (k/n) is the Kronecker symbol. - Robin Visser, Mar 13 2024

Crossrefs

Programs

  • Magma
    [p : p in PrimesUpTo(3000) | p mod 84 in [47, 59, 83]];  // Robin Visser, Mar 13 2024

Formula

The primes are congruent to {47, 59, 83} (mod 84). - Robin Visser, Mar 13 2024

Extensions

More terms from Robin Visser, Mar 13 2024
Showing 1-4 of 4 results.