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.

A160736 Toothpick sequence starting from a right angle formed by 2 toothpicks: a(n)=A160406(n)*2.

Original entry on oeis.org

0, 2, 4, 8, 12, 16, 20, 28, 36, 40, 44, 52, 60, 68, 80, 100, 116, 120, 124, 132, 140, 148, 160, 180, 196, 204, 216, 236, 256, 280, 320, 372, 404, 408, 412, 420, 428, 436, 448, 468, 484, 492, 504, 524, 544, 568
Offset: 0

Views

Author

Omar E. Pol, May 25 2009

Keywords

Crossrefs

Extensions

Terms after a(9) from Nathaniel Johnston, Mar 31 2011

A160738 Toothpick sequence starting from a T formed by 3 toothpicks: a(n)=A160406(n)*3.

Original entry on oeis.org

0, 3, 6, 12, 18, 24, 30, 42, 54, 60, 66, 78, 90, 102, 120, 150, 174, 180, 186, 198, 210, 222, 240, 270, 294, 306, 324, 354, 384, 420, 480, 558, 606, 612, 618, 630, 642, 654, 672, 702, 726, 738, 756, 786, 816, 852, 912, 990, 1038, 1050, 1068, 1098, 1128, 1164
Offset: 0

Views

Author

Omar E. Pol, May 25 2009, Jun 19 2009

Keywords

Crossrefs

Extensions

More terms from R. J. Mathar, Jul 28 2009

A160731 First differences of A160730.

Original entry on oeis.org

2, 2, 4, 6, 6, 6, 12, 14, 12, 6, 12, 14, 16, 18, 32, 34, 20, 6, 12, 14, 16, 18, 32, 34, 24, 18, 32, 38, 44, 62, 92, 82, 36, 6, 12, 14, 16, 18, 32, 34, 24, 18, 32, 38, 44, 62, 92, 82, 40, 18, 32, 38, 44, 62
Offset: 1

Views

Author

Omar E. Pol, May 25 2009

Keywords

Examples

			Placing the entries starting from a(4) in a triangle with rows that have length equal to powers of two gives:
6, 6
6, 12, 14, 12
6, 12, 14, 16, 18, 32, 34, 20
6, 12, 14, 16, 18, 32, 34, 24, 18, 32, 38, 44, 62, 92, 82, 36
...
The rows of this triangle tend to 2*A168114.
		

Crossrefs

Formula

From Nathaniel Johnston, Mar 28 2011: (Start)
a(n) = 2*A168113(n)
a(2^(n+2) + 1) = 4(2^n + 1), n >= 1.
(End)

Extensions

Terms after a(11) from Nathaniel Johnston, Mar 28 2011

A160733 First differences of A160732.

Original entry on oeis.org

3, 3, 6, 8, 8, 6, 12, 14, 8, 8, 16, 20, 18, 18, 30, 26, 8, 8, 16, 20, 18, 20, 34, 32, 20, 28, 48, 54, 50, 60, 78, 50, 8, 8, 16, 20, 18, 20, 34, 32, 20, 28, 48, 54, 50, 62, 82, 56, 20, 28, 48, 54, 52, 70, 96
Offset: 1

Views

Author

Omar E. Pol, May 25 2009

Keywords

Crossrefs

Extensions

Terms after a(9) from Nathaniel Johnston, Mar 30 2011

A335338 P_5(2n+1), the Legendre polynomial of order 5 at 2n+1.

Original entry on oeis.org

1, 1683, 23525, 129367, 458649, 1256651, 2904733, 5950575, 11138417, 19439299, 32081301, 50579783, 76767625, 112825467, 161311949, 225193951, 307876833, 413234675, 545640517, 709996599, 911764601, 1156995883, 1452361725, 1805183567, 2223463249, 2715913251, 3291986933
Offset: 0

Views

Author

Seiichi Manyama, Jun 02 2020

Keywords

Crossrefs

Row 5 of A335333.
Cf. A160737.

Programs

  • Mathematica
    a[n_] := LegendreP[5, 2*n + 1]; Array[a, 27, 0] (* Amiram Eldar, May 03 2021 *)
  • PARI
    a(n) = pollegendre(5, 2*n+1)
    
  • PARI
    a(n) = 252*n^5+630*n^4+560*n^3+210*n^2+30*n+1
    
  • PARI
    N=40; x='x+O('x^N); Vec((1+x)*(1+1676*x+11766*x^2+1676*x^3+x^4)/(1-x)^6)

Formula

a(n) = A160737(2*n+1)/4.
a(n) = 252*n^5 + 630*n^4 + 560*n^3 + 210*n^2 + 30*n + 1 = (2*n + 1) * (126*n^4 + 252*n^3 + 154*n^2 + 28*n + 1).
G.f.: (1+x)*(1+1676*x+11766*x^2+1676*x^3+x^4)/(1-x)^6.
Showing 1-5 of 5 results.