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 31-33 of 33 results.

A130304 Triangle, (1,1,0,0,1,1,0,0,...) in every column.

Original entry on oeis.org

1, 1, 1, 0, 1, 1, 0, 0, 1, 1, 1, 0, 0, 1, 1, 1, 1, 0, 0, 1, 1, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1
Offset: 1

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Author

Gary W. Adamson, May 20 2007

Keywords

Examples

			First few rows of the triangle:
  1;
  1, 1;
  0, 1, 1;
  0, 0, 1, 1;
  1, 0, 0, 1, 1;
  1, 1, 0, 0, 1, 1;
  ...
		

Crossrefs

Cf. A004524 (row sums), A130305 (binomial transform).

Extensions

Missing 0 inserted at a(30) and more terms from Georg Fischer, Jul 28 2023

A347650 Number of minimum total dominating sets in the n-pan graph (for n > 2).

Original entry on oeis.org

1, 2, 3, 2, 3, 8, 5, 2, 5, 18, 7, 2, 7, 32, 9, 2, 9, 50, 11, 2, 11, 72, 13, 2, 13, 98, 15, 2, 15, 128, 17, 2, 17, 162, 19, 2, 19, 200, 21, 2, 21, 242, 23, 2, 23, 288, 25, 2, 25, 338, 27, 2, 27, 392, 29, 2, 29, 450, 31, 2, 31, 512, 33, 2, 33, 578, 35, 2, 35, 648
Offset: 1

Views

Author

Eric W. Weisstein, Sep 09 2021

Keywords

Comments

Sequence extended to a(1) using the formula/recurrence.
The total domination number is given by A004524(n + 2). - Andrew Howroyd, Jun 11 2025

Crossrefs

Programs

  • Mathematica
    Table[Piecewise[{{(n + 3)/2, Mod[n, 4] == 3}, {2, Mod[n, 4] == 0}, {(n + 1)/2, Mod[n, 4] == 1}, {(n + 2)^2/8, Mod[n, 4] == 2}}], {n, 20}]
    LinearRecurrence[{0, 0, 0, 3, 0, 0, 0, -3, 0, 0, 0, 1}, {1, 2, 3, 2, 3, 8, 5, 2, 5, 18, 7, 2}, 20]
    CoefficientList[Series[(-1 - 2 x - 3 x^2 - 2 x^3 - 2 x^5 + 4 x^6 + 4 x^7 + x^8 - x^10 - 2 x^11)/(-1 + x^4)^3, {x, 0, 20}], x]

Formula

a(n) = (n+3)/2 for n = 3 (mod 4)
= 2 for n = 0 (mod 4)
= (n+1)/2 for n = 1 (mod 3)
= (n+2)^2/8 for n = 2 (mod 4).
a(n) = 3*a(n-4)-3*a(n-8)+a(n-12) for n > 12.
G.f.: x*(-1-2*x-3*x^2-2*x^3-2*x^5+4*x^6+4*x^7+x^8-x^10-2*x^11)/(-1+x^4)^3.

A004528 Ratios of successive terms are 1,2,2,2,3,4,4,4,5,6,6,6,7,...

Original entry on oeis.org

1, 1, 2, 4, 8, 24, 96, 384, 1536, 7680, 46080, 276480, 1658880, 11612160, 92897280, 743178240, 5945425920, 53508833280, 535088332800, 5350883328000, 53508833280000, 588597166080000, 7063165992960000
Offset: 0

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Author

Keywords

Crossrefs

Cf. A004524.
Previous Showing 31-33 of 33 results.