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.

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A172309 Number of L-toothpicks added to the L-toothpick structure of A172308 (First quadrant) at the n-th stage.

Original entry on oeis.org

0, 1, 2, 2, 2, 4, 4, 2, 4, 6, 6, 8, 6, 12, 10, 6, 4, 6, 10, 12, 10, 14, 14, 16, 16, 18, 14, 16, 12, 20, 22, 8, 8, 16, 18, 16, 10, 16, 20, 24, 26, 36, 24, 32, 30, 40, 28, 24
Offset: 0

Views

Author

Omar E. Pol, Feb 06 2010

Keywords

Crossrefs

Formula

a(0) = 0, a(n) = A172305(n+1)/4, for n>=1.

Extensions

More terms from Colin Barker, Apr 19 2015

A172313 a(n) = A172309(n+1)/2.

Original entry on oeis.org

1, 1, 1, 2, 2, 1, 2, 3, 3, 4, 3, 6, 5, 3, 2, 3, 5, 6, 5, 7, 7, 8, 8, 9, 7, 8, 6, 10, 11, 4, 4, 8, 9, 8, 5, 8, 10, 12, 13, 18, 12, 16, 15, 20, 14, 12
Offset: 1

Views

Author

Omar E. Pol, Feb 06 2010

Keywords

Crossrefs

Extensions

a(16)-a(46) from Robert Price, Jun 17 2019

A173531 a(0)=0: For n>0, a(n) = A060632(n)*A060632(n-1).

Original entry on oeis.org

0, 1, 2, 4, 4, 4, 8, 16, 8, 4, 8, 16, 16, 16, 32, 64, 16, 4, 8, 16, 16, 16, 32, 64, 32, 16, 32, 64, 64, 64, 128, 256, 32, 4, 8, 16, 16, 16, 32, 64, 32, 16, 32, 64, 64, 64, 128, 256, 64, 16, 32, 64, 64, 64, 128, 256, 128, 64, 128, 256, 256
Offset: 0

Views

Author

Omar E. Pol, Oct 10 2010

Keywords

Comments

First differences of A173530.
Number of triangles (Or V-toothpicks, or L-toothpicks, etc.) added in the three-dimensional structure of A173530 at the n-th stage.

Examples

			If written as a triangle, begins:
0;
1;
2;
4,4;
4,8,16,8;
4,8,16,16,16,32,64,16;
4,8,16,16,16,32,64,32,16,32,64,64,64,128,256,32;
4,8,16,16,16,32,64,32,16,32,64,64,64,128,256,64,16,32,64,64,64,128,256,128,...
		

Crossrefs

Programs

  • Mathematica
    Prepend[Times @@@ Partition[Array[2^DigitCount[Floor[#/2], 2, 1] &, 120, 0], 2, 1], 0] (* Michael De Vlieger, Jan 11 2024 *)

A173532 a(n) = A173531(n) - A139251(n).

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 4, 4, 0, 4, 32, 0, 0, 0, 4, 4, 0, 4, 32, 12, 0, 4, 28, 24, 4, 40, 176, 0, 0, 0, 4, 4, 0, 4, 32, 12, 0, 4, 28, 24, 4, 40, 176, 28, 0, 4, 28, 24, 4, 40, 172, 72, 4, 36, 144, 116, 48, 256, 832, 0, 0, 0, 4, 4, 0, 4, 32, 12, 0, 4
Offset: 0

Views

Author

Omar E. Pol, Oct 10 2010

Keywords

Examples

			If written as a triangle, begins:
0;
0;
0,0;
0,0,0,4;
0,0,0,4,4,0,4,32;
0,0,0,4,4,0,4,32,12,0,4,28,24,4,40,176;
0,0,0,4,4,0,4,32,12,0,4,28,24,4,40,176,28,0,4,28,24,4,40,172,72,4,36,144,116,48,256,832;
		

Crossrefs

Previous Showing 11-14 of 14 results.