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 21-23 of 23 results.

A333018 Number of free heptagonal polyforms with n cells on the heptagonal tiling of the hyperbolic plane.

Original entry on oeis.org

1, 1, 1, 3, 10, 44, 249, 1513, 9992, 68305, 480748, 3450793, 25186583
Offset: 0

Views

Author

Peter Kagey, Mar 05 2020

Keywords

Comments

The heptagonal tiling is represented by Schläfli symbol {7,3}.
This sequence is to A259352 what A000228 is to A108070.
This sequence is computed from via program by Christian Sievers in the Code Golf Stack Exchange link.

Crossrefs

Analogs with different Schläfli symbols are A000105 ({4,4}), A000207 ({3,oo}), A000228 ({6,3}), A000577 ({3,6}), A005036 ({4,oo}), A119611 ({4,5}), A330659 ({3,7}), and A332930 ({4,6}).

Extensions

a(9)-a(12) from Ed Wynn, Feb 14 2021

A173496 Partial sums of A005036.

Original entry on oeis.org

1, 2, 4, 9, 25, 85, 346, 1589, 7846, 40567, 216327, 1180227, 6554627, 36939883, 210777514, 1215644593, 7077255068, 41546269583, 245708229893, 1462853468378, 8761861115930, 52767463557770
Offset: 1

Views

Author

Jonathan Vos Post, Feb 19 2010

Keywords

Comments

Partial sums of number of ways of dissecting a polygon into n quadrilaterals. The subsequence of primes in this partial sum begins: 2, 6554627, 36939883, 1215644593.

Examples

			a(22) = 1 + 1 + 2 + 5 + 16 + 60 + 261 + 1243 + 6257 + 32721 + 175760 + 963900 + 5374400 + 30385256 + 173837631 + 1004867079 + 5861610475 + 34469014515 + 204161960310 + 1217145238485 + 7299007647552 + 44005602441840.
		

Crossrefs

Formula

a(n) = SUM[i=1..n] A005036(i).

A330211 Number of free pentagonal polyforms with n cells on the order-4 pentagonal tiling of the hyperbolic plane.

Original entry on oeis.org

1, 1, 1, 2, 8, 28, 143, 747, 4346, 25974, 160869, 1015723, 6531611, 42592880
Offset: 0

Views

Author

Peter Kagey, Mar 05 2020

Keywords

Comments

The order-4 pentagonal tiling of the hyperbolic plane has Schläfli symbol {5,4}.
This sequence is computed from via program by Christian Sievers in the Code Golf Stack Exchange link.

Crossrefs

Analogs with different Schläfli symbols are A000105 ({4,4}), A000207 ({3,oo}), A000228 ({6,3}), A000577 ({3,6}), A005036 ({4,oo}), A119611 ({4,5}), A330659 ({3,7}), A332930 ({4,6}), and A333018 ({7,3}).

Programs

  • C
    // See the Code Golf link.
  • GAP
    # See the Code Golf link.
    
  • bc
    # See the Code Golf link.
    

Extensions

a(8)-a(13) from Ed Wynn, Feb 16 2021
Previous Showing 21-23 of 23 results.