A059804 -id:A059804 - cp's OEIS frontend

A047896 For given n, consider all 4-tuples P = (a,b,c,d) with P.P = n; let d = squared distance to the line OP from the closest point of Z^n (excluding the endpoints); sequence gives max_P d*n.

1, 1, 2, 3, 1, 2, 3, 0, 2, 4, 2, 3, 3, 3, 5, 0, 2, 5, 3, 4, 5, 6, 5, 0, 6, 4, 5, 3, 5, 9, 6, 0, 6, 8, 6, 8, 9, 8, 9, 0, 5, 6, 5, 8, 9, 11, 10, 0, 6, 11, 9, 4, 10, 11, 10, 0, 14, 9, 11, 11, 9, 11, 14, 0, 14, 11, 11, 8, 11, 19, 14, 0, 9, 11, 11, 8, 10, 14, 14, 0, 14, 10, 13, 20, 21

Offset: 1

N. J. A. Sloane and Vinay Vaishampayan, Feb 27 2001

nonn

A form of generalized GCD of 4 numbers.

			n=10, best P is (1,1,2,2), closest point of Z^4 to OP is (0,0,1,1) at squared distance d = 2/5, so a(10) = 10*2/5 = 4.

N. J. A. Sloane, Vinay A. Vaishampayan and Sueli I. R. Costa, Fat Struts: Constructions and a Bound, Proceedings Information Theory Workshop, Taormino, Italy, 2009. [Cached copy]
N. J. A. Sloane, Vinay A. Vaishampayan and Sueli I. R. Costa, A Note on Projecting the Cubic Lattice, Discrete and Computational Geometry, Vol. 46 (No. 3, 2011), 472-478.
N. J. A. Sloane, Vinay A. Vaishampayan and Sueli I. R. Costa, The Lifting Construction: A General Solution to the Fat Strut Problem, Proceedings International Symposium on Information Theory (ISIT), 2010, IEEE Press. [Cached copy]

Cf. A059804, A059774.

A059774 Consider the line segment in R^n from the origin to the point P=(1,2,3,...,n); let d = squared distance to this line from the closest point of Z^n (excluding the endpoints). Sequence gives d times P.P.

Original entry on oeis.org

1, 3, 9, 21, 40, 75, 120, 189, 285, 385, 506, 650, 819, 1015, 1240, 1496, 1785, 2109, 2470, 2870, 3311, 3795, 4324, 4900, 5525, 6201, 6930, 7714, 8555, 9455, 10416, 11440, 12529, 13685, 14910, 16206, 17575, 19019, 20540, 22140, 23821, 25585, 27434, 29370

Offset: 2

N. J. A. Sloane and Vinay Vaishampayan, Feb 21 2001

P.P is given by A000330(n). For n >= 10, a(n) = A000330(n-1).

Officially these are just conjectures so far.

N. J. A. Sloane, Vinay A. Vaishampayan and Sueli I. R. Costa, Fat Struts: Constructions and a Bound, Proceedings Information Theory Workshop, Taormino, Italy, 2009. [Cached copy]
N. J. A. Sloane, Vinay A. Vaishampayan and Sueli I. R. Costa, A Note on Projecting the Cubic Lattice, Discrete and Computational Geometry, Vol. 46 (No. 3, 2011), 472-478.
N. J. A. Sloane, Vinay A. Vaishampayan and Sueli I. R. Costa, The Lifting Construction: A General Solution to the Fat Strut Problem, Proceedings International Symposium on Information Theory (ISIT), 2010, IEEE Press. [Cached copy]

Cf. A000330, A059804, A047896.

A137609 Consider a line in n-space given parametrically by y(t)=v*t, where v is the vector (2,3,5,..prime(n)). Let t0>0 be the least value of t such that y(t0) is closest to an integer point not on the line y(t). a(n) is t0 times v.v.

Original entry on oeis.org

5, 15, 36, 91, 145, 305, 476, 729, 408, 1295, 1796, 1072, 1370, 1749, 2226, 2816, 3426, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229

Offset: 2

T. D. Noe, Jan 29 2008

nonn

See A059804 for the distance from y(t0) to the integer point. Observe that for n >= 19, a(n) = prime(n). For n >= 19, the closest integer point is (0,0,0,..,0,1).

A060454 Consider the line segment in R^n from the origin to the point v = (1,4,9,...,n^2); let d = squared distance to this line from the closest point of Z^n (excluding the endpoints). Sequence gives d times v.v.

Original entry on oeis.org

1, 6, 38, 107, 350, 728, 1752, 3090, 6215, 9878, 17654, 26117, 42924, 60256, 93024, 125460, 184509, 241110, 341110, 434511, 595562, 742808, 991640, 1215110, 1586403, 1914822, 2452646, 2922185, 3681560, 4337024, 5385600, 6281704, 7701561, 8904294, 10793862, 12381939, 14822755, 16907891, 19221332, 21781332, 24607093, 27718789, 31137590

Offset: 0

N. J. A. Sloane, Apr 09 2001

nonn

v.v is given by A000538(n).

Officially these are just conjectures so far.

N. J. A. Sloane, Vinay A. Vaishampayan and Sueli I. R. Costa, Fat Struts: Constructions and a Bound, Proceedings Information Theory Workshop, Taormino, Italy, 2009. [Cached copy]
N. J. A. Sloane, Vinay A. Vaishampayan and Sueli I. R. Costa, A Note on Projecting the Cubic Lattice, Discrete and Computational Geometry, Vol. 46 (No. 3, 2011), 472-478.
N. J. A. Sloane, Vinay A. Vaishampayan and Sueli I. R. Costa, The Lifting Construction: A General Solution to the Fat Strut Problem, Proceedings International Symposium on Information Theory (ISIT), 2010, IEEE Press. [Cached copy]

Cf. A059804.

For n<=37, a(n) = A060452(n); for n >= 38, a(n) = A000538(n-1).

cp's OEIS Frontend

A047896 For given n, consider all 4-tuples P = (a,b,c,d) with P.P = n; let d = squared distance to the line OP from the closest point of Z^n (excluding the endpoints); sequence gives max_P d*n.

Views

Author

Keywords

Comments

Examples

Links

Crossrefs

A059774 Consider the line segment in R^n from the origin to the point P=(1,2,3,...,n); let d = squared distance to this line from the closest point of Z^n (excluding the endpoints). Sequence gives d times P.P.

Views

Author

Keywords

Comments

Links

Crossrefs

A137609 Consider a line in n-space given parametrically by y(t)=v*t, where v is the vector (2,3,5,..prime(n)). Let t0>0 be the least value of t such that y(t0) is closest to an integer point not on the line y(t). a(n) is t0 times v.v.

Views

Author

Keywords

Comments

A060454 Consider the line segment in R^n from the origin to the point v = (1,4,9,...,n^2); let d = squared distance to this line from the closest point of Z^n (excluding the endpoints). Sequence gives d times v.v.

Views

Author

Keywords

Comments

Links

Crossrefs

Formula