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 1-8 of 8 results.

A367598 Record high-points in A367356.

Original entry on oeis.org

17, 164, 490, 1472, 39819, 119228, 3225387, 9657464, 261256395, 782254580, 21161768043
Offset: 1

Views

Author

N. J. A. Sloane, Nov 24 2023

Keywords

Comments

This is the base-3 analog of A367364.

Crossrefs

Extensions

a(7)-a(11) from Michael S. Branicky, Nov 27 2023

A367599 Indices of record high-points in A367356.

Original entry on oeis.org

1, 6, 7, 18, 162, 1458, 13122, 118098, 1062882, 9565938, 86093442
Offset: 1

Views

Author

N. J. A. Sloane, Nov 24 2023

Keywords

Comments

This is a base-3 analog of A367365. The present sequence includes the terms 2*3, 2*3^2, 2*3^6, whereas A367365 includes 4*10 and 4*10^3.
Terms a(4)-a(11) are of the form 2*3^(2*i), i > 0. - Michael S. Branicky, Nov 26 2023

Crossrefs

Extensions

a(7)-a(11) from Michael S. Branicky, Nov 27 2023

A367355 Comma sequence, analogous to A121805, starting at 1, but the calculations are done in base 3.

Original entry on oeis.org

1, 5, 12, 13, 17, 25, 29, 36, 37, 41, 48, 49, 53, 61, 66, 68, 76
Offset: 1

Views

Author

N. J. A. Sloane, Nov 18 2023

Keywords

Crossrefs

A367605 and A367605 give the length and last term for the analogous sequence in base b.

Programs

  • Maple
    # Comma Successor in Maple in base "bas", from N. J. A. Sloane, Dec 06 2023
    bas := 3;
    Ldigit:=proc(n) local v; v:=convert(n, base, bas); v[-1]; end; # Returns leading digit
    # Return comma-successor to a or -1 if no successor exists
    commsucc := proc(a) local f,i,d;
    f := (a mod bas);
    d:=bas*f;
    for i from 1 to bas-1 do
    d := d+1;
    if Ldigit(a+d) = i then return(a+d); fi;
    od:
    return(-1);
    end;
    a:=[1]; s:=1; for n from 1 to 16 do s:=commsucc(s); a:=[op(a),s]; od: a;

A367606 Comma-successor to n working in base 3, but written in base 10, or -1 if n has no successor.

Original entry on oeis.org

5, 9, 4, -1, 12, 8, 11, 15, 10, 14, 19, 13, 17, 22, 16, 21, 25, 20, 24, 27, 23, -1, 30, 26, 29, 33, 28, 32, 36, 31, 35, 39, 34, 38, 42, 37, 41, 45, 40, 44, 48, 43, 47, 51, 46, 50, 55, 49, 53, 58, 52, 57, 61, 56, 60, 64, 59, 63, 67, 62, 66, 70, 65, 69, 73, 68, 72, 76, 71, 75, 79, 74, 78, 81, 77, -1, 84, 80, 83, 87, 82
Offset: 1

Views

Author

N. J. A. Sloane, Dec 11 2023

Keywords

Comments

This is a base-3 analog of A367338.
It seems that the indices of the terms equal to -1 are in A168613. - Ivan N. Ianakiev, Dec 12 2023
This is true for A168613(n), n >= 2. See proofs in A367341. - Michael S. Branicky, Dec 15 2023

Crossrefs

Programs

  • Python
    from sympy.ntheory.factor_ import digits
    def a(n):
        b = n + 3*(n%3)
        return next((b+y for y in [1, 2] if digits(b+y, 3)[1] == y), -1)
    print([a(n) for n in range(1, 82)]) # Michael S. Branicky, Dec 11 2023

A367609 Comma-number associated with A367607(n), and written in base 3, or -1 if A367607(n) = -1.

Original entry on oeis.org

11, 21, 1, -1, 21, 2, 11, 21, 1, 11, 22, 1, 11, 22, 1, 12, 22, 2, 12, 21, 2, -1, 21, 2, 11, 21, 1, 11, 21, 1, 11, 21, 1, 11, 21, 1, 11, 21, 1, 11, 21, 1, 11, 21, 1, 11, 22, 1, 11, 22, 1, 12, 22, 2, 12, 22, 2, 12, 22, 2, 12, 22, 2, 12, 22, 2, 12, 22, 2, 12, 22, 2, 12, 21, 2, -1, 21, 2, 11, 21, 1, 11, 21, 1, 11, 21, 1, 11, 21, 1, 11, 21, 1, 11, 21, 1, 11, 21, 1, 11
Offset: 1

Views

Author

N. J. A. Sloane, Dec 11 2023

Keywords

Comments

This is a base-3 analog of A367339.

Crossrefs

Programs

  • Python
    from sympy.ntheory.factor_ import digits
    def a(n):
        b = n + 3*(n%3)
        return next((int("".join(map(str, digits(b+y-n, 3)[1:]))) for y in [1, 2] if digits(b+y, 3)[1] == y), -1)
    print([a(n) for n in range(1, 101)]) # Michael S. Branicky, Dec 11 2023

A367608 Comma-number associated with A367606(n), but written in base 10, or -1 if A367606(n) = -1.

Original entry on oeis.org

4, 7, 1, -1, 7, 2, 4, 7, 1, 4, 8, 1, 4, 8, 1, 5, 8, 2, 5, 7, 2, -1, 7, 2, 4, 7, 1, 4, 7, 1, 4, 7, 1, 4, 7, 1, 4, 7, 1, 4, 7, 1, 4, 7, 1, 4, 8, 1, 4, 8, 1, 5, 8, 2, 5, 8, 2, 5, 8, 2, 5, 8, 2, 5, 8, 2, 5, 8, 2, 5, 8, 2, 5, 7, 2, -1, 7, 2, 4, 7, 1, 4, 7, 1, 4, 7, 1, 4, 7, 1, 4, 7, 1, 4, 7, 1, 4, 7, 1, 4
Offset: 1

Views

Author

N. J. A. Sloane, Dec 11 2023

Keywords

Comments

If n has a comma-successor m (say) in base 3, then a(n) is the comma-number linking n and m, and is equal to m-n; a(n) = -1 if n has no successor. See A367338 for definitions.
This is a base-3 analog of A367339.

Crossrefs

Programs

  • Python
    from sympy.ntheory.factor_ import digits
    def a(n):
        b = n + 3*(n%3)
        return next((b+y-n for y in [1, 2] if digits(b+y, 3)[1] == y), -1)
    print([a(n) for n in range(1, 101)]) # Michael S. Branicky, Dec 11 2023

A367607 Comma-successor to n working in base 3, and written in base 3, or -1 if n has no successor.

Original entry on oeis.org

12, 100, 11, -1, 110, 22, 102, 120, 101, 112, 201, 111, 122, 211, 121, 210, 221, 202, 220, 1000, 212, -1, 1010, 222, 1002, 1020, 1001, 1012, 1100, 1011, 1022, 1110, 1021, 1102, 1120, 1101, 1112, 1200, 1111, 1122, 1210, 1121, 1202, 1220, 1201, 1212, 2001, 1211, 1222, 2011, 1221, 2010, 2021, 2002, 2020, 2101, 2012, 2100
Offset: 1

Views

Author

N. J. A. Sloane, Dec 11 2023

Keywords

Comments

This is a base-3 analog of A367338.

Crossrefs

Programs

  • Python
    from sympy.ntheory.factor_ import digits
    def a(n):
        b = n + 3*(n%3)
        return next((int("".join(map(str, d3))) for y in [1, 2] if (d3:=digits(b+y, 3)[1:])[0] == y), -1)
    print([a(n) for n in range(1, 61)]) # Michael S. Branicky, Dec 11 2023

A367623 Number of comma-children of n in base 3.

Original entry on oeis.org

2, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1
Offset: 1

Views

Author

N. J. A. Sloane, Dec 23 2023

Keywords

Crossrefs

Programs

  • Python
    from sympy.ntheory.factor_ import digits
    def a(k, base=3):
        m = k + base*(k%base)
        return len([m+y for y in range(1, base) if digits(m+y, base)[1] == y])
    print([a(n) for n in range(1, 96)]) # Michael S. Branicky, Dec 23 2023
Showing 1-8 of 8 results.