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.

A060372 p(n), positive part of n when n=p(n)-q(n) with p(n), q(n), p(n)+q(n) in A005836, integers written without 2 in base 3.

Original entry on oeis.org

0, 1, 3, 3, 4, 9, 9, 10, 9, 9, 10, 12, 12, 13, 27, 27, 28, 27, 27, 28, 30, 30, 31, 27, 27, 28, 27, 27, 28, 30, 30, 31, 36, 36, 37, 36, 36, 37, 39, 39, 40, 81, 81, 82, 81, 81, 82, 84, 84, 85, 81, 81, 82, 81, 81, 82, 84, 84, 85, 90, 90, 91, 90, 90, 91, 93, 93, 94, 81, 81, 82, 81
Offset: 0

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Author

Claude Lenormand (claude.lenormand(AT)free.fr), Apr 02 2001

Keywords

Comments

The graphs of p(n), q(n) are fractals; the graph of p(n)+q(n) is Sierpiński-like.

Examples

			Example: 14=27-13=3^3 -(3^0+3^1+3^2), 16=28-12=3^3+3^0 -(3^1+3^2), 20=30-10=3^3+3^1 -(3^0+3^2); 27+13=28+12=30+10=40; 10,12,13, 27, 28, 30 are written without 2 in base 3.
		

Crossrefs

Programs

A060373 q(n), negative part of n when n=p(n)-q(n) with p(n), q(n), p(n)+q(n) in A005836, integers written without 2 in base 3.

Original entry on oeis.org

0, 0, 1, 0, 0, 4, 3, 3, 1, 0, 0, 1, 0, 0, 13, 12, 12, 10, 9, 9, 10, 9, 9, 4, 3, 3, 1, 0, 0, 1, 0, 0, 4, 3, 3, 1, 0, 0, 1, 0, 0, 40, 39, 39, 37, 36, 36, 37, 36, 36, 31, 30, 30, 28, 27, 27, 28, 27, 27, 31, 30, 30, 28, 27, 27, 28, 27, 27, 13, 12, 12, 10, 9, 9, 10, 9, 9, 4, 3, 3, 1, 0, 0, 1, 0
Offset: 0

Views

Author

Claude Lenormand (claude.lenormand(AT)free.fr), Apr 02 2001

Keywords

Crossrefs

Programs

A343316 Array T(n, k), n, k > 0, read by antidiagonals; the balanced ternary representation of T(n, k) is obtained by multiplying componentwise the digits in the balanced ternary representations of n and of k.

Original entry on oeis.org

0, 0, 0, 0, 1, 0, 0, -1, -1, 0, 0, 0, 4, 0, 0, 0, 1, 3, 3, 1, 0, 0, -1, 2, 3, 2, -1, 0, 0, 0, -2, 3, 3, -2, 0, 0, 0, 1, -3, -3, 4, -3, -3, 1, 0, 0, -1, -4, -3, -4, -4, -3, -4, -1, 0, 0, 0, 1, -3, -3, 13, -3, -3, 1, 0, 0, 0, 1, 0, 0, -2, 12, 12, -2, 0, 0, 1, 0
Offset: 0

Views

Author

Rémy Sigrist, Apr 11 2021

Keywords

Comments

For any k >= 0, n -> T(n, k) is 3^A134021(k)-periodic.
The zeros of the table form a Vicsek fractal (see illustration in Links section).

Examples

			Array T(n, k) begins:
  n\k|  0   1   2   3   4   5   6   7   8  9  10  11  12
  ---+--------------------------------------------------
    0|  0   0   0   0   0   0   0   0   0  0   0   0   0
    1|  0   1  -1   0   1  -1   0   1  -1  0   1  -1   0
    2|  0  -1   4   3   2  -2  -3  -4   1  0  -1   4   3
    3|  0   0   3   3   3  -3  -3  -3   0  0   0   3   3
    4|  0   1   2   3   4  -4  -3  -2  -1  0   1   2   3
    5|  0  -1  -2  -3  -4  13  12  11  10  9   8   7   6
    6|  0   0  -3  -3  -3  12  12  12   9  9   9   6   6
    7|  0   1  -4  -3  -2  11  12  13   8  9  10   5   6
    8|  0  -1   1   0  -1  10   9   8  10  9   8  10   9
    9|  0   0   0   0   0   9   9   9   9  9   9   9   9
   10|  0   1  -1   0   1   8   9  10   8  9  10   8   9
   11|  0  -1   4   3   2   7   6   5  10  9   8  13  12
   12|  0   0   3   3   3   6   6   6   9  9   9  12  12
Array T(n, k) begins in balanced ternary notation (with "T" instead of digits "-1"):
  n\k|  0  1  1T  10  11  1TT  1T0  1T1  10T  100  101  11T  110
  ---+----------------------------------------------------------
    0|  0  0   0   0   0    0    0    0    0    0    0    0    0
    1|  0  1   T   0   1    T    0    1    T    0    1    T    0
   1T|  0  T  11  10  1T   T1   T0   TT    1    0    T   11   10
   10|  0  0  10  10  10   T0   T0   T0    0    0    0   10   10
   11|  0  1  1T  10  11   TT   T0   T1    T    0    1   1T   10
  1TT|  0  T  T1  T0  TT  111  110  11T  101  100  10T  1T1  1T0
  1T0|  0  0  T0  T0  T0  110  110  110  100  100  100  1T0  1T0
  1T1|  0  1  TT  T0  T1  11T  110  111  10T  100  101  1TT  1T0
  10T|  0  T   1   0   T  101  100  10T  101  100  10T  101  100
  100|  0  0   0   0   0  100  100  100  100  100  100  100  100
  101|  0  1   T   0   1  10T  100  101  10T  100  101  10T  100
  11T|  0  T  11  10  1T  1T1  1T0  1TT  101  100  10T  111  110
  110|  0  0  10  10  10  1T0  1T0  1T0  100  100  100  110  110
		

Crossrefs

Programs

  • PARI
    T(n,k) = { if (n==0 || k==0, return (0), my (d=centerlift(Mod(n,3)), t=centerlift(Mod(k,3))); d*t + 3*T((n-d)\3, (k-t)\3)) }

Formula

T(n, k) = T(k, n).
T(m, T(n, k)) = T(T(m, n), k).
T(n, 0) = 0.
T(n, 1) = A102283(n).
T(n, n) = A060374(n).
Showing 1-3 of 3 results.