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 1-3 of 3 results.

A139493 Primes of the form x^2 + 9x*y + y^2 for x and y nonnegative.

Original entry on oeis.org

11, 23, 37, 53, 67, 71, 113, 137, 163, 179, 191, 317, 331, 379, 389, 401, 421, 443, 449, 463, 487, 499, 599, 617, 631, 641, 653, 683, 709, 751, 757, 823, 863, 883, 907, 911, 947, 977, 991, 1061, 1087, 1093, 1103, 1171, 1213, 1303, 1367, 1373, 1409, 1423
Offset: 1

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Author

Artur Jasinski, Apr 24 2008

Keywords

Comments

This is a member of the family of sequences of primes of the forms x^2 + kxy + y^2.
See for k=1 A007645 = x^2+3y^2, k=2 squares no primes, k=3 A038872, k=4 A068228 = x^2+9y^2, k=5 A139492, k=6 A007519 = x^2+8y^2, k=7 A033212 = x^2+15y^2, k=8 A107152 = x^2+45y^2, k=9 A139493, k=10 A107008 = x^2+24y^2, k=11 A139494, k=12 A139495, k=13 A139496, k=14* = 10 A107008 = x^2+24y^2, k=15 A139497, k=16 A033215 = x^2+21y^2, k=17 A139498, k=18 A107145 = x^2+40y^2, k=19 A139499, k=20 A139500, k=21 A139501, k=22 A139502, k=23 A139503, k=24 A139504, k=25 A139505, k=26,A139506, k=27 A139507, k=28 A139508, k=29 A139509, k=30 A139510, k=31 A139511, k=32 A139512

Crossrefs

Programs

  • Mathematica
    a = {}; w = 9; k = 1; Do[Do[If[PrimeQ[n^2 + w*n*m + k*m^2], AppendTo[a, n^2 + w*n*m + k*m^2]], {n, m, 400}], {m, 1, 400}]; Union[a] (*Artur Jasinski*)

A139539 Indices of numbers of form 12k+1 which are prime and have representation x^2+32xy+y^2.

Original entry on oeis.org

19, 29, 34, 35, 55, 64, 69, 85, 89, 104, 115, 119, 129, 149, 150, 155, 174, 180, 189, 199, 250, 255, 259, 265, 269, 289, 324, 335, 344, 350, 370, 405, 409, 425, 454, 460, 489, 490, 510, 539, 540, 544, 565, 579, 580, 609, 614, 624, 629, 630, 639, 675, 680, 684
Offset: 1

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Author

Artur Jasinski, Apr 25 2008

Keywords

Crossrefs

A139540 Indices of primes of the form 12k+1 which have representation x^2+32xy+y^2.

Original entry on oeis.org

10, 15, 18, 19, 26, 31, 32, 38, 40, 48, 51, 52, 55, 65, 66, 67, 74, 77, 79, 84, 100, 103, 104, 107, 109, 117, 131, 132, 135, 138, 143, 154, 155, 161, 169, 170, 182, 183, 187, 198, 199, 200, 208, 212, 213, 222, 225, 229, 231, 232, 235, 247, 248, 249, 255, 258
Offset: 1

Views

Author

Artur Jasinski, Apr 25 2008

Keywords

Crossrefs

Showing 1-3 of 3 results.