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.

Previous Showing 31-34 of 34 results.

A158937 Numbers of the form x^2+3y^2 where x and y are positive integers (with repetitions).

Original entry on oeis.org

4, 7, 12, 13, 16, 19, 21, 28, 28, 28, 31, 36, 37, 39, 43, 48, 49, 52, 52, 52, 57, 61, 63, 64, 67, 73, 76, 76, 76, 79, 84, 84, 84, 91, 91, 93, 97, 100, 103, 108, 109, 111, 112, 112, 112, 117, 124, 124, 124, 127, 129, 133, 133, 139, 144, 147, 148, 148, 148, 151, 156, 156, 156, 157, 163, 169, 171, 172, 172, 172, 175, 181, 183, 189, 192, 193, 196, 196, 196, 196, 199, 201, 208, 208, 208, 211, 217, 217, 219, 223, 228, 228, 228, 229, 237, 241, 244, 244, 244, 247
Offset: 1

Views

Author

Zak Seidov, Mar 26 2011

Keywords

Comments

Least integer m with exactly n repetitions, {m,n}: {4,1},{91,2},{28,3},{196,4},{31213,5},{364,6}, {9604,7},{53599,8},{2548,9},{470596,10}.
This is an important quadratic form with a small determinant, so a list of its values with repetition is of interest. - N. J. A. Sloane, Apr 02 2011

Examples

			m=28: {x,y}={5,1},{4,2},{1,3}.
		

Crossrefs

Cf. A092572 Numbers of the form x^2+3y^2 where x and y are positive integers.

A155572 Intersection of A000404, A154777 and A154778: N = a^2 + b^2 = c^2 + 2d^2 = e^2 + 5f^2 for some positive integers a,b,c,d,e,f.

Original entry on oeis.org

41, 89, 164, 225, 241, 281, 356, 369, 401, 409, 449, 521, 569, 601, 641, 656, 761, 769, 801, 809, 881, 900, 929, 964, 1009, 1025, 1049, 1124, 1129, 1201, 1249, 1289, 1321, 1361, 1409, 1424, 1476, 1481, 1489, 1521, 1601, 1604, 1609, 1636, 1681, 1721, 1796
Offset: 1

Views

Author

M. F. Hasler, Jan 25 2009

Keywords

Crossrefs

Programs

  • PARI
    isA155572(n,/* optional 2nd arg allows us to get other sequences */c=[5,2,1]) = { for(i=1,#c, for(b=1,sqrtint((n-1)\c[i]), issquare(n-c[i]*b^2) & next(2)); return);1}
    for( n=1,1999, isA155572(n) & print1(n","))

A155711 Intersection of A154777 and A155717: N = a^2 + 2b^2 = c^2 + 7d^2 for some positive integers a,b,c,d.

Original entry on oeis.org

11, 43, 44, 67, 72, 88, 99, 107, 113, 121, 137, 144, 163, 172, 176, 179, 193, 211, 233, 268, 275, 281, 288, 331, 337, 344, 347, 352, 379, 387, 396, 401, 428, 443, 449, 452, 457, 473, 484, 491, 499, 536, 539, 547, 548, 569, 571, 576, 603, 617, 641, 648, 652
Offset: 1

Views

Author

M. F. Hasler, Jan 25 2009

Keywords

Crossrefs

Programs

  • PARI
    isA155711(n,/* optional 2nd arg allows us to get other sequences */c=[7,2]) = { for(i=1,#c, for(b=1,sqrtint((n-1)\c[i]), issquare(n-c[i]*b^2) & next(2)); return);1}
    for( n=1,999, isA155711(n) & print1(n","))

A155713 Intersection of A154778 and A155716: N = a^2 + 5b^2 = c^2 + 6d^2 for some positive integers a,b,c,d.

Original entry on oeis.org

49, 70, 105, 145, 150, 166, 196, 214, 225, 241, 249, 280, 294, 321, 406, 409, 420, 441, 454, 505, 580, 600, 601, 609, 630, 664, 681, 694, 721, 726, 745, 769, 784, 841, 856, 870, 886, 889, 900, 934, 945, 964, 996, 1009, 1030, 1041, 1089, 1120, 1126, 1129
Offset: 1

Views

Author

M. F. Hasler, Jan 25 2009

Keywords

Crossrefs

Programs

  • PARI
    isA155713(n,/* optional 2nd arg allows us to get other sequences */c=[6,5]) = { for(i=1,#c, for(b=1,sqrtint((n-1)\c[i]), issquare(n-c[i]*b^2) & next(2)); return);1}
    for( n=1,999, isA155713(n) & print1(n","))
Previous Showing 31-34 of 34 results.