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.

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A277645 Beatty sequence for 3+sqrt(6).

Original entry on oeis.org

5, 10, 16, 21, 27, 32, 38, 43, 49, 54, 59, 65, 70, 76, 81, 87, 92, 98, 103, 108, 114, 119, 125, 130, 136, 141, 147, 152, 158, 163, 168, 174, 179, 185, 190, 196, 201, 207, 212, 217, 223, 228, 234, 239, 245, 250, 256, 261, 267, 272, 277, 283, 288, 294, 299, 305
Offset: 1

Views

Author

Jason Kimberley, Oct 26 2016

Keywords

Comments

Eggleton et al. show that k is in this sequence if and only if A277515(k) > 3.

Examples

			a(4) = 3*4 + 9 because 9^2 = 81 < 6*4^2 = 96 < 100 = 10^2.
		

References

  • R. B. Eggleton, J. S. Kimberley, and J. A. MacDougall, Square-free rank of integers, submitted.

Crossrefs

Complement of A277644.

Programs

  • Magma
    [3*n+Isqrt(6*n^2): n in [1..60]];
  • Mathematica
    Floor[Range[100]*(3 + Sqrt[6])] (* Paolo Xausa, Jul 11 2024 *)

Formula

a(n) = floor(n*(3+sqrt(6))).
a(n) = 3*n + A000196(A033581(n)).
a(n) = A008585(n) + A000196(A033581(n)).

A004564 Expansion of sqrt(6) in base 5.

Original entry on oeis.org

2, 2, 1, 1, 0, 4, 3, 1, 1, 4, 3, 1, 1, 3, 3, 1, 3, 4, 1, 2, 1, 4, 1, 1, 2, 1, 2, 4, 4, 3, 0, 1, 4, 1, 3, 0, 1, 0, 4, 4, 0, 3, 3, 1, 1, 1, 4, 3, 0, 0, 0, 0, 0, 3, 1, 2, 2, 0, 4, 1, 1, 2, 0, 0, 2, 3, 1, 4, 1, 0, 3, 1, 3, 3, 3, 0, 1, 2, 3, 0, 3, 1, 4, 1, 0, 0, 3, 2, 2, 0, 0, 0, 0, 3, 3, 2, 3, 2, 3
Offset: 1

Views

Author

Keywords

Examples

			In base 5: sqrt(11) = 2.21104311431133134121411...
		

Crossrefs

Programs

  • Magma
    d:= 6; m:=5; Prune(Reverse(IntegerToSequence(Isqrt(d*m^100), m))); // G. C. Greubel, Mar 26 2018
  • Mathematica
    RealDigits[Sqrt[6], 5, 100][[1]] (* Alonso del Arte, Aug 27 2012 *)

Extensions

Updated by Alois P. Heinz at the suggestion of Kevin Ryde, Feb 19 2012

A154236 a(n) = ( (5 + sqrt(6))^n - (5 - sqrt(6))^n )/(2*sqrt(6)).

Original entry on oeis.org

1, 10, 81, 620, 4661, 34830, 259741, 1935640, 14421321, 107436050, 800355401, 5962269060, 44415937981, 330876267670, 2464859855061, 18361949464880, 136787157402641, 1018994534193690, 7590989351286721, 56548997363187100
Offset: 1

Views

Author

Al Hakanson (hawkuu(AT)gmail.com), Jan 05 2009

Keywords

Comments

First differences are in A164551.
Lim_{n -> infinity} a(n)/a(n-1) = 5 + sqrt(6) = 7.4494897427....

Crossrefs

Cf. A010464 (decimal expansion of square root of 6), A164551.

Programs

  • Magma
    Z:=PolynomialRing(Integers()); N:=NumberField(x^2-6); S:=[ ((5+r)^n-(5-r)^n)/(2*r): n in [1..25] ]; [ Integers()!S[j]: j in [1..#S] ]; // Klaus Brockhaus, Jan 07 2009
    
  • Mathematica
    LinearRecurrence[{10, -19}, {1, 10}, 25] (* or *) Table[Simplify[((5 + Sqrt[6])^n -(5-Sqrt[6])^n)/(2*Sqrt[6])], {n, 1, 25}] (* G. C. Greubel, Sep 06 2016 *)
  • PARI
    a(n)=([0,1; -19,10]^(n-1)*[1;10])[1,1] \\ Charles R Greathouse IV, Sep 07 2016
  • Sage
    [lucas_number1(n,10,19) for n in range(1, 25)] # Zerinvary Lajos, Apr 26 2009
    

Formula

From Philippe Deléham, Jan 06 2009: (Start)
a(n) = 10*a(n-1) - 19*a(n-2) for n > 1, with a(0)=0, a(1)=1.
G.f.: x/(1 - 10*x + 19*x^2). (End)

Extensions

Extended beyond a(7) by Klaus Brockhaus, Jan 07 2009
Edited by Klaus Brockhaus, Oct 04 2009

A171539 Decimal expansion of sqrt(6/35).

Original entry on oeis.org

4, 1, 4, 0, 3, 9, 3, 3, 5, 6, 0, 5, 4, 1, 2, 5, 3, 0, 6, 7, 7, 6, 7, 6, 1, 1, 8, 7, 7, 6, 2, 7, 9, 1, 9, 2, 0, 8, 9, 7, 1, 8, 0, 8, 2, 1, 3, 5, 9, 7, 0, 6, 5, 9, 6, 7, 7, 0, 2, 6, 4, 2, 3, 0, 6, 0, 5, 1, 8, 4, 1, 0, 6, 4, 7, 2, 4, 8, 0, 1, 2, 0, 4, 8, 9, 3, 0, 3, 7, 6, 9, 1, 4, 3, 8, 9, 0, 7, 1, 3, 6, 4, 3, 7, 2
Offset: 0

Views

Author

R. J. Mathar, Dec 11 2009

Keywords

Comments

The absolute value of the Clebsch-Gordan coupling coefficient = <2 3/2 ; -2 3/2 | 5/2 -1/2>.

Examples

			sqrt(6/35) = sqrt(210)/35 = 0.414039335605412530677676118776...
		

Programs

  • Mathematica
    RealDigits[Sqrt[6/35],10,120][[1]] (* Harvey P. Dale, Jun 09 2023 *)

Formula

A174925 Decimal expansion of (2+sqrt(6))/4.

Original entry on oeis.org

1, 1, 1, 2, 3, 7, 2, 4, 3, 5, 6, 9, 5, 7, 9, 4, 5, 2, 4, 5, 4, 9, 3, 2, 1, 0, 1, 8, 6, 7, 6, 4, 7, 2, 8, 4, 7, 9, 9, 1, 4, 8, 6, 8, 7, 0, 1, 6, 4, 1, 6, 7, 5, 3, 2, 1, 0, 8, 1, 7, 3, 1, 4, 1, 8, 1, 2, 7, 4, 0, 0, 9, 4, 3, 6, 4, 3, 2, 8, 7, 5, 6, 6, 3, 4, 9, 6, 4, 8, 5, 8, 2, 7, 6, 1, 6, 0, 0, 5, 8, 7, 0, 4, 6, 4
Offset: 1

Views

Author

Klaus Brockhaus, Apr 02 2010

Keywords

Comments

Continued fraction expansion of (2+sqrt(6))/4 is A010689.

Examples

			(2+sqrt(6))/4 = 1.11237243569579452454...
		

Crossrefs

Cf. A010464 (decimal expansion of sqrt(6)), A010689 (repeat 1, 8).

Programs

A176051 Decimal expansion of (2+sqrt(6))/2.

Original entry on oeis.org

2, 2, 2, 4, 7, 4, 4, 8, 7, 1, 3, 9, 1, 5, 8, 9, 0, 4, 9, 0, 9, 8, 6, 4, 2, 0, 3, 7, 3, 5, 2, 9, 4, 5, 6, 9, 5, 9, 8, 2, 9, 7, 3, 7, 4, 0, 3, 2, 8, 3, 3, 5, 0, 6, 4, 2, 1, 6, 3, 4, 6, 2, 8, 3, 6, 2, 5, 4, 8, 0, 1, 8, 8, 7, 2, 8, 6, 5, 7, 5, 1, 3, 2, 6, 9, 9, 2, 9, 7, 1, 6, 5, 5, 2, 3, 2, 0, 1, 1, 7, 4, 0, 9, 2, 9
Offset: 1

Views

Author

Klaus Brockhaus, Apr 07 2010

Keywords

Comments

Continued fraction expansion of (2+sqrt(6))/2 is A010694.
a(n) = A115754(n) for n > 1; a(1) = 2.

Examples

			(2+sqrt(6))/2 = 2.22474487139158904909...
Note also that (1+sqrt(6))/2 = 1.724744871391589049098642..., the mis-typed golden ratio. - _N. J. A. Sloane_, Jan 19 2025
		

Crossrefs

Cf. A010464 (decimal expansion of sqrt(6)), A115754 (decimal expansion of sqrt(3/2)), A010694 (repeat 2, 4).
See also A379800.

Programs

  • Mathematica
    RealDigits[(2+Sqrt[6])/2,10,120][[1]]  (* Harvey P. Dale, Apr 21 2011 *)

A176213 Decimal expansion of 2+sqrt(6).

Original entry on oeis.org

4, 4, 4, 9, 4, 8, 9, 7, 4, 2, 7, 8, 3, 1, 7, 8, 0, 9, 8, 1, 9, 7, 2, 8, 4, 0, 7, 4, 7, 0, 5, 8, 9, 1, 3, 9, 1, 9, 6, 5, 9, 4, 7, 4, 8, 0, 6, 5, 6, 6, 7, 0, 1, 2, 8, 4, 3, 2, 6, 9, 2, 5, 6, 7, 2, 5, 0, 9, 6, 0, 3, 7, 7, 4, 5, 7, 3, 1, 5, 0, 2, 6, 5, 3, 9, 8, 5, 9, 4, 3, 3, 1, 0, 4, 6, 4, 0, 2, 3, 4, 8, 1, 8, 5, 9
Offset: 1

Views

Author

Klaus Brockhaus, Apr 12 2010

Keywords

Comments

Continued fraction expansion of 2+sqrt(6) is A010694.
a(n) = A010464(n) = A086180(n) for n > 1, a(1) = 4.

Examples

			2+sqrt(6) = 4.44948974278317809819...
		

Crossrefs

Cf. A010464 (decimal expansion of sqrt(6)), A086180 (decimal expansion of 1+sqrt(6)), A010694 (repeat 4, 2).

Programs

  • Mathematica
    RealDigits[2+Sqrt[6],10,120][[1]] (* Harvey P. Dale, Aug 19 2018 *)

A004563 Expansion of sqrt(6) in base 4.

Original entry on oeis.org

2, 1, 3, 0, 3, 0, 1, 0, 1, 3, 0, 0, 2, 2, 0, 0, 1, 0, 2, 1, 0, 0, 2, 1, 1, 3, 0, 3, 3, 2, 2, 0, 0, 1, 2, 1, 0, 0, 3, 0, 2, 0, 2, 2, 0, 1, 2, 1, 0, 0, 3, 1, 0, 2, 2, 2, 2, 3, 0, 2, 0, 3, 2, 1, 3, 2, 3, 1, 2, 0, 0, 1, 0, 1, 1, 0, 0, 3, 2, 2, 1, 3, 2, 3, 3, 1, 2, 2, 0, 2, 3, 1, 3, 3, 0, 0, 1, 3, 2
Offset: 1

Views

Author

Keywords

Crossrefs

Cf. A010464.

Programs

  • Magma
    d:= 6; m:=4; Prune(Reverse(IntegerToSequence(Isqrt(d*m^100), m))); // G. C. Greubel, Mar 26 2018
  • Mathematica
    RealDigits[Sqrt[6],4,120][[1]] (* Harvey P. Dale, May 06 2011 *)

A004565 Expansion of sqrt(6) in base 6.

Original entry on oeis.org

2, 2, 4, 1, 0, 3, 1, 2, 2, 0, 5, 5, 2, 1, 4, 5, 3, 2, 5, 0, 0, 4, 3, 2, 0, 4, 0, 4, 1, 1, 0, 5, 5, 2, 0, 5, 3, 2, 1, 0, 4, 3, 2, 0, 1, 5, 5, 0, 3, 1, 1, 1, 5, 3, 4, 1, 3, 3, 1, 2, 2, 3, 1, 5, 2, 4, 0, 1, 5, 4, 3, 0, 3, 0, 4, 4, 0, 4, 0, 2, 5, 3, 2, 5, 2, 5, 4, 3, 5, 1, 1, 0, 4, 5, 5, 3, 5, 5, 3
Offset: 1

Views

Author

Keywords

Crossrefs

Cf. A010464.

Programs

  • Magma
    d:= 6; m:=6; Prune(Reverse(IntegerToSequence(Isqrt(d*m^100), m))); // G. C. Greubel, Mar 26 2018
  • Mathematica
    RealDigits[Sqrt[6], 6, 100][[1]] (* G. C. Greubel, Mar 26 2018 *)

Extensions

Updated by Alois P. Heinz at the suggestion of Kevin Ryde, Feb 19 2012

A004566 Expansion of sqrt(6) in base 7.

Original entry on oeis.org

2, 3, 1, 0, 1, 1, 4, 0, 0, 6, 3, 0, 0, 5, 2, 3, 4, 1, 1, 2, 1, 6, 2, 5, 6, 6, 1, 6, 3, 2, 0, 5, 4, 5, 0, 1, 5, 1, 6, 6, 6, 6, 4, 2, 6, 1, 1, 3, 2, 6, 6, 0, 5, 4, 6, 3, 1, 3, 6, 6, 2, 4, 0, 4, 4, 1, 0, 1, 0, 2, 3, 2, 2, 3, 4, 5, 5, 6, 1, 2, 5, 5, 0, 1, 6, 4, 6, 2, 4, 2, 0, 0, 4, 5, 0, 6, 2, 3, 6
Offset: 1

Views

Author

Keywords

Crossrefs

Cf. A010464.

Programs

  • Magma
    d:= 6; m:=7; Prune(Reverse(IntegerToSequence(Isqrt(d*m^100), m))); // G. C. Greubel, Mar 26 2018
  • Mathematica
    RealDigits[Sqrt[6], 7, 100][[1]] (* G. C. Greubel, Mar 26 2018 *)

Extensions

Updated by Alois P. Heinz at the suggestion of Kevin Ryde, Feb 19 2012
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