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 1-3 of 3 results.

A337132 a(n) is the number of squares at distance n from the central square of a Vicsek fractal.

Original entry on oeis.org

1, 4, 4, 4, 12, 4, 4, 12, 4, 4, 12, 12, 12, 36, 4, 4, 12, 4, 4, 12, 12, 12, 36, 4, 4, 12, 4, 4, 12, 12, 12, 36, 12, 12, 36, 12, 12, 36, 36, 36, 108, 4, 4, 12, 4, 4, 12, 12, 12, 36, 4, 4, 12, 4, 4, 12, 12, 12, 36, 12, 12, 36, 12, 12, 36, 36, 36, 108, 4, 4, 12
Offset: 0

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Author

Rémy Sigrist, Nov 21 2020

Keywords

Comments

For symmetry reasons, a(n) is a multiple of 4 for any n > 0.

Links

Crossrefs

See A337018 for similar sequences.
Cf. A153775.

Programs

  • PARI
    See Links section.

Formula

a(n) = 4 iff n belongs to A153775.

A337545 a(n) is the number of pentagons at distance n from the central pentagon of a pentaflake.

Original entry on oeis.org

1, 5, 10, 5, 15, 20, 10, 30, 15, 15, 20, 50, 25, 25, 50, 30, 50, 40, 80, 35, 65, 30, 30, 45, 55, 40, 40, 80, 140, 30, 90, 55, 35, 80, 80, 55, 65, 150, 60, 100, 90, 110, 80, 140, 100, 70, 120, 210, 70, 170, 105, 125, 100, 180, 45, 55, 90, 60, 80, 110, 105, 65
Offset: 0

Views

Author

Rémy Sigrist, Nov 22 2020

Keywords

Comments

For symmetry reasons, a(n) is a multiple of 5 for any n > 0.

Links

Crossrefs

See A337018 for similar sequences.

A339124 a(n) is the number of squares at distance n from the central square of a golden square fractal.

Original entry on oeis.org

1, 4, 12, 28, 60, 132, 300, 692, 1596, 3668, 8412, 19284, 44220, 101428, 232668, 533716, 1224252, 2808180, 6441372, 14775188, 33891324, 77739956, 178319964, 409030356, 938233788, 2152120564, 4936534044, 11323421716, 25973664636, 59578391604
Offset: 0

Views

Author

Rémy Sigrist, Nov 24 2020

Keywords

Comments

For symmetry reasons, a(n) is a multiple of 4 for any n > 0.

Links

Crossrefs

See A337018 for similar sequences.
Cf. A269962 (partial sums).

Formula

G.f.: (2*x^4 - 2*x^2 - x - 1)/(2*x^4 - 2*x^2 + 3*x - 1).
a(0) = 1.
a(n) = A269962(n+1) - A269962(n) for any n > 0.
a(n) = 3*a(n-1) - 2*a(n-2) + 2*a(n-4) for n > 4. - Stefano Spezia, Dec 02 2020
Showing 1-3 of 3 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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