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 1-5 of 5 results.

A085569 Denominator of 2*Sum(C(n,w)/(2*w+1),w=0..n/2-1)+C(n,n/2)/(n+1) if n is even, or of 2*Sum(C(n,w)/(2*w+1),w=0..(n-1)/2) if n is odd.

Original entry on oeis.org

1, 1, 3, 1, 15, 3, 7, 15, 45, 5, 231, 21, 455, 315, 45, 3, 1683, 3465, 7315, 5005, 3003, 143, 13455, 585, 6825, 13923, 3213, 6545, 515185, 17765, 110143, 31977, 2078505, 62985, 1789515, 51129, 210197, 426075, 246675, 6325, 1400355, 34155, 41612175, 84192075
Offset: 0

Views

Author

N. J. A. Sloane, Jul 07 2003

Keywords

Examples

			1, 2, 8/3, 4, 88/15, 28/3, 104/7, 376/15, 1904/45, 372/5, 30152/231, ...
		

Crossrefs

Programs

  • Maple
    b := binomial; f1 := n->if n mod 2 = 0 then 2*add(b(n,w)/(2*w+1),w=0..n/2-1)+b(n,n/2)/(n+1); else 2*add(b(n,w)/(2*w+1),w=0..(n-1)/2); fi;

A085570 If n mod 2 = 0 then 2*Sum(floor(C(n,w)/(2*w+1)),w=0..n/2-1)+floor(C(n,n/2)/(n+1)) otherwise 2*Sum(floor(C(n,w)/(2*w+1)),w=0..(n-1)/2).

Original entry on oeis.org

1, 2, 2, 4, 5, 8, 14, 24, 39, 74, 128, 232, 423, 776, 1426, 2660, 4931, 9268, 17346, 32840, 61903, 117832, 223410, 427156, 813812, 1561830, 2987535, 5751742, 11039759, 21312036, 41025866, 79386066, 153208323, 297072312, 574604611, 1116186954, 2163216427
Offset: 0

Views

Author

N. J. A. Sloane, Jul 07 2003

Keywords

Crossrefs

Programs

  • Maple
    b := binomial; f2 := n->if n mod 2 = 0 then 2*add(floor(b(n,w)/(2*w+1)),w=0..n/2-1)+floor(b(n,n/2)/(n+1)); else 2*add(floor(b(n,w)/(2*w+1)),w=0..(n-1)/2); fi;

A085571 Numerator of 2*Sum(C(n,w)/w,w=1..n/2-1)+C(n,n/2)/(n/2) if n is even otherwise of 2*Sum(C(n,w)/w,w=1..(n-1)/2).

Original entry on oeis.org

2, 6, 11, 20, 101, 175, 593, 173, 1502, 2684, 28649, 52169, 662393, 1224077, 4506259, 4210067, 23506871, 44294491, 41572193, 78849257, 1639049932, 3125022742, 23750582143, 9095291663, 225666905951, 144544431373, 276913262539, 76244134117, 732674442397
Offset: 2

Views

Author

N. J. A. Sloane, Jul 07 2003

Keywords

Examples

			2, 6, 11, 20, 101/3, 175/3, 593/6, 173, 1502/5, 2684/5, 28649/30, ...
		

Crossrefs

Programs

  • Maple
    b := binomial; f3 := n->if n mod 2 = 0 then 2*add(b(n,w)/w,w=1..n/2-1)+b(n,n/2)/(n/2); else 2*add(b(n,w)/w,w=1..(n-1)/2); fi;

A085572 Denominator of 2*Sum(C(n,w)/w,w=1..n/2-1)+C(n, n/2)/(n/2) if n is even otherwise of 2*Sum(C(n,w)/w,w=1..(n-1)/2).

Original entry on oeis.org

1, 1, 1, 1, 3, 3, 6, 1, 5, 5, 30, 30, 210, 210, 420, 210, 630, 630, 315, 315, 3465, 3465, 13860, 2772, 36036, 12012, 12012, 1716, 8580, 8580, 17160, 8580, 145860, 204204, 612612, 612612, 11639628, 11639628, 29099070, 29099070, 29099070, 29099070, 1322685, 14549535
Offset: 2

Views

Author

N. J. A. Sloane, Jul 07 2003

Keywords

Examples

			2, 6, 11, 20, 101/3, 175/3, 593/6, 173, 1502/5, 2684/5, 28649/30, ...
		

Crossrefs

Programs

  • Maple
    b := binomial; f3 := n->if n mod 2 = 0 then 2*add(b(n,w)/w,w=1..n/2-1)+b(n, n/2)/(n/2); else 2*add(b(n,w)/w,w=1..(n-1)/2); fi;

A085573 2*Sum(floor(C(n,w)/w),w=1..n/2-1)+floor(C(n,n/2)/(n/2)) if n is even, otherwise 2*Sum(floor(C(n,w)/w),w=1..(n-1)/2).

Original entry on oeis.org

2, 6, 11, 20, 32, 56, 97, 172, 298, 534, 952, 1736, 3150, 5824, 10724, 20042, 37308, 70304, 131971, 250308, 473020, 901872, 1713596, 3281122, 6262254, 12033330, 23053047, 44431308, 85393280, 165008114, 318009610, 615878180, 1189803926, 2308781688
Offset: 2

Views

Author

N. J. A. Sloane, Jul 07 2003

Keywords

Crossrefs

Programs

  • Maple
    b := binomial; f3 := n->if n mod 2 = 0 then 2*add(floor(b(n,w)/w),w=1..n/2-1)+floor(b(n,n/2)/(n/2)); else 2*add(floor(b(n,w)/w),w=1..(n-1)/2); fi;
Showing 1-5 of 5 results.