A104457 -id:A104457 - cp's OEIS frontend

A139342 Decimal expansion of e^(-(1+sqrt(5))/2).

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

Offset: 0

Mohammad K. Azarian, Apr 14 2008

By the Lindemann-Weierstrass theorem, this constant is transcendental. - Charles R Greathouse IV, May 13 2019

			0.19828815286220623226788895660486467084208489250129...

Index entries for transcendental numbers.

Cf. A001622, A094214, A104457, A098317, A002390, A139339, A139340, A139341.

evalf(exp(1)^(-(1+sqrt(5))/2),100); # Wesley Ivan Hurt, Feb 09 2017

RealDigits[E^-GoldenRatio,10,120][[1]] (* Harvey P. Dale, Dec 30 2020 *)

exp(-(sqrt(5)+1)/2) \\ Charles R Greathouse IV, May 13 2019

Equals exp(-A001622).

Equals 1/A139341. - Amiram Eldar, Feb 08 2022

Leading zero removed by R. J. Mathar, Feb 05 2009

A094885 Decimal expansion of phi*e, where phi = (1 + sqrt(5))/2.

Original entry on oeis.org

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

Offset: 1

N. J. A. Sloane, Jun 15 2004

Matches the value of the infinite nested radical corresponding to the sequence {e^(2^n), n=1,2,3,...}, i.e., a = sqrt(e^2+sqrt(e^4+...)), which converges by Vijayaraghavan's theorem. Proof: write the golden ratio as phi = sqrt(1+ sqrt(1+ sqrt(1+...))). Then e*phi = e*sqrt(1+ sqrt(1+ sqrt(1+ ...))) = sqrt(e^2+ e^2*sqrt(1+ sqrt(1+ ...))) = sqrt(e^2+ sqrt(e^4+ e^4*sqrt(1+ ...))) = ... = a. Evidently, the 'e' could stand for any constant, not just e; for example phi itself as in A104457, or Pi as in A094886. - Stanislav Sykora, May 24 2016

			4.398272389447946...

Harry J. Smith, Table of n, a(n) for n = 1..20000
Eric Weisstein's World of Mathematics, Nested Radical
Index entries for transcendental numbers

Cf. A001113, A001622, A104457, A094886.

First@ RealDigits[N[GoldenRatio E, 120]] (* Michael De Vlieger, May 24 2016 *)

default(realprecision, 20080); phi=(1+sqrt(5))/2; x=phi*exp(1); for (n=1, 20000, d=floor(x); x=(x-d)*10; write("b094885.txt", n, " ", d)); \\ Harry J. Smith, Apr 27 2009

exp(1)*(1+sqrt(5))/2 \\ Michel Marcus, May 25 2016

A202543 Decimal expansion of the number x satisfying e^(x/2) - e^(-x/2) = 1.

Original entry on oeis.org

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

Offset: 0

Clark Kimberling, Dec 21 2011

See A202537 for a guide to related sequences. The Mathematica program includes a graph.
W. Gawronski et al. in their paper - see ref. below - obtained the asymptotics for the Chebyshev-Stirling numbers. In the algebraic description of the respective "asymptotic coefficients" the number x = 2*log phi, where phi is the golden section, play the central role. - Roman Witula, Feb 02 2015
Also two times the Lévy measure for the continued fraction of the golden section, i.e., A202543/log(2) is the mean number of bits gained from the next convergent of the continued fraction representation. (See also Dan Lascu in links.) - A.H.M. Smeets, Jun 06 2018

			0.9624236501192068949955178268487368462703686...

W. Gawronski, L. L. Littlejohn, and T. Neuschel, Asymptotics of Stirling and Chebyshev-Stirling numbers of the second kind, arXiv:1308.6803 [math.CO], 2013.
W. Gawronski, L. L. Littlejohn, and T. Neuschel, Asymptotics of Stirling and Chebyshev-Stirling numbers of the second kind, Studies in Applied Mathematics by MIT 133 (2014), 1-17.
Dan Lascu, A Gauss-Kuzmintype problem for a family of continued fraction expansions, Journal of Number Theory 133 (2013), 2153-2181.
Index entries for transcendental numbers

Cf. A001622, A002390, A104457, A202537, A202543.

u = 1/2; v = 1/2;
f[x_] := E^(u*x) - E^(-v*x); g[x_] := 1
Plot[{f[x], g[x]}, {x, 0, 2}, {AxesOrigin -> {0, 0}}]
r = x /. FindRoot[f[x] == g[x], {x, .9, 1}, WorkingPrecision -> 110]
RealDigits[r]    (* A202543 *)
RealDigits[ Log[ (3+Sqrt[5])/2], 10, 99] // First (* Jean-François Alcover, Feb 27 2013 *)
RealDigits[ FindRoot[ Exp[x/2] == 1 +  Exp[-x/2] , {x, 0}, WorkingPrecision -> 128][[1, 2]]][[1]] (* Robert G. Wilson v, Jun 13 2018 *)

2*asinh(1/2) \\ Michel Marcus, Jun 24 2018, after A002390

Equals 2*A002390. - A.H.M. Smeets, Jun 06 2018
From Amiram Eldar, Aug 21 2020: (Start)
Equals log(A104457) = log(1 + A001622).
Equals 2*arcsinh(1/2). [corrected by Georg Fischer, Jul 12 2021]
Equals Sum_{k>=0} (-1)^k*binomial(2*k,k)/((2*k+1)*16^k). (End)
Equals Pi*i + Sum_{k>=0} arctanh(phi^(2^k))/2^k, with phi = A001622 and i = sqrt(-1). - Antonio Graciá Llorente, Feb 13 2025

Typo in name fixed by Jean-François Alcover, Feb 27 2013

A200135 Decimal expansion of the negated value of the digamma function at 1/5.

Original entry on oeis.org

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

Offset: 1

R. J. Mathar, Nov 13 2011

			Psi(1/5) =  -5.289039896592188295547207962...

G. C. Greubel, Table of n, a(n) for n = 1..10000
Wikipedia, Digamma function
Index entries for sequences related to the digamma function

Cf. A020759, A047787, A020777, A200064, A200134, A200136, A200137, A200138.

SetDefaultRealField(RealField(100)); R:= RealField(); -EulerGamma(R) -Pi(R)*Sqrt(1+2/Sqrt(5))/2 -5*Log(5)/4 -Sqrt(5)/4*Log((3+Sqrt(5)/2) ); // G. C. Greubel, Sep 03 2018

-gamma-Pi*sqrt(1+2/sqrt(5))/2-5*log(5)/4-sqrt(5)/4*log((3+sqrt(5)/2) ); evalf(%) ;

RealDigits[-PolyGamma[1/5], 10, 105] // First (* Jean-François Alcover, Feb 11 2013 *)

-psi(1/5) \\ Charles R Greathouse IV, Jul 19 2013

Psi(1/5) = -gamma - Pi*sqrt(1 + 2/sqrt(5))/2 - 5*log(5)/4 -sqrt(5)*log((3 + sqrt(5))/2)/4 where gamma = A001620, sqrt(1 + 2/sqrt(5)) = A019952, (3 + sqrt(5))/2 = A104457.

More terms from Jean-François Alcover, Feb 11 2013

A377805 Decimal expansion of the volume of a snub dodecahedron with unit edge length.

Original entry on oeis.org

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

Offset: 2

Paolo Xausa, Nov 09 2024

			37.616649962733362975777673671302714340355289873...

Eric Weisstein's World of Mathematics, Snub Dodecahedron.
Wikipedia, Snub dodecahedron.
Index entries for algebraic numbers, degree 12.

Cf. A377804 (surface area), A377806 (circumradius), A377807 (midradius).
Cf. A102769 (analogous for a regular dodecahedron).
Cf. A001622, A090550, A104457, A134946, A377849.

First[RealDigits[((3*GoldenRatio + 1)*#*(# + 1) - GoldenRatio/6 - 2)/Sqrt[3*#^2 - GoldenRatio^2], 10, 100]] & [Root[#^3 + 2*#^2 - GoldenRatio^2 &, 1]] (* or *)
First[RealDigits[PolyhedronData["SnubDodecahedron", "Volume"], 10, 100]]

Equals ((3*phi + 1)*xi*(xi + 1) - phi/6 - 2)/sqrt(3*xi^2 - phi^2) = (A090550*xi*(xi + 1) - A134946 - 2)/sqrt(3*xi^2 - A104457), where phi = A001622 and xi = A377849.

Equals the largest real root of 2176782336*x^12 - 3195335070720*x^10 + 162223191936000*x^8 + 1030526618040000*x^6 + 6152923794150000*x^4 - 182124351550575000*x^2 + 187445810737515625.

A026273 a(n) = least k such that s(k) = n, where s = A026272.

Original entry on oeis.org

1, 2, 4, 6, 7, 9, 10, 12, 14, 15, 17, 19, 20, 22, 23, 25, 27, 28, 30, 31, 33, 35, 36, 38, 40, 41, 43, 44, 46, 48, 49, 51, 53, 54, 56, 57, 59, 61, 62, 64, 65, 67, 69, 70, 72, 74, 75, 77, 78, 80, 82, 83, 85, 86, 88, 90, 91, 93, 95, 96, 98, 99

Offset: 1

Clark Kimberling

nonn

This is the lower s-Wythoff sequence, where s(n)=n+1.
See A184117 for the definition of lower and upper s-Wythoff sequences.  The first few terms of a and its complement, b=A026274, are obtained generated as follows:
s=(2,3,4,5,6,...);
a=(1,2,4,6,7,...)=A026273;
b=(3,5,8,11,13,...)=A026274.
Briefly:  b=s+a, and a=mex="least missing".
From Michel Dekking, Mar 12 2018: (Start)
One has r*(n-2*r+3) = n*r-2r^2+3*r = (n+1)*r-2.
So  a(n) = (n+1)*r-2, and we see that this sequence is simply the Beatty sequence of the golden ratio, shifted spatially and temporally. In other words: if w = A000201 = 1,3,4,6,8,9,11,12,14,...  is the lower Wythoff sequence, then a(n) = w(n+2) - 2.
(N.B. As so often, there is the 'offset 0 vs 1 argument', w = A000201 has offset 1; it would have been better to give (a(n)) offset 1, too).
This observation also gives an answer to Lenormand's question, and a simple proof of Mathar's conjecture in A059426.
(End)

Jon Asier Bárcena-Petisco, Luis Martínez, María Merino, Juan Manuel Montoya, and Antonio Vera-López, Fibonacci-like partitions and their associated piecewise-defined permutations, arXiv:2503.19696 [math.CO], 2025. See p. 3.

Cf. A184117, A026274.

r=(1+Sqrt[5])/2;
a[n_]:=Floor[r*(n-2r+3)];
b[n_]:=Floor[r*r*(n+2r-3)];
Table[a[n],{n,200}]   (* A026273 *)
Table[b[n],{n,200}]   (* A026274 *)

a(n) = floor[r*(n-2*r+3)], where r=golden ratio.

b(n) = floor[(r^2)*(n+2*r-3)] = floor(n*A104457-A134972+1).

Extended by Clark Kimberling, Jan 14 2011

A139345 Decimal expansion of sine of the golden ratio. That is, the decimal expansion of sin((1+sqrt(5))/2).

Original entry on oeis.org

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

Offset: 0

Mohammad K. Azarian, Apr 15 2008

By the Lindemann-Weierstrass theorem, this constant is transcendental. - Charles R Greathouse IV, May 13 2019

			0.99888450909488479883326824263012904463865119212705...

Mohammad K. Azarian, Problem 123, Missouri Journal of Mathematical Sciences, Vol. 10, No. 3 (Fall 1998), p. 176; Solution, ibid., Vol. 12, No. 1 (Winter 2000), pp. 61-62.
Index entries for transcendental numbers.

Cf. A001622, A094214, A104457, A098317, A002390, A139339, A139340, A139341, A139342, A139350.

RealDigits[Sin[GoldenRatio], 10, 100][[1]] (* Amiram Eldar, Feb 07 2022 *)

sin((1+sqrt(5))/2) \\ Charles R Greathouse IV, May 13 2019

Equals sin(A001622).

Equals 1/A139350. - Amiram Eldar, Feb 07 2022

Leading zero removed by R. J. Mathar, Feb 05 2009

A139346 Decimal expansion of cosine of the golden ratio, negated. That is, the decimal expansion of -cos((1+sqrt(5))/2).

Original entry on oeis.org

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

Offset: 0

Mohammad K. Azarian, Apr 15 2008

By the Lindemann-Weierstrass theorem, this constant is transcendental. - Charles R Greathouse IV, May 13 2019

			-0.04722009625435983376687869404879456549554899472734...

Index entries for transcendental numbers.

Cf. A001622, A094214, A104457, A098317, A002390, A139339, A139340, A139341, A139342, A139345, A139349.

Join[{0}, RealDigits[Cos[GoldenRatio], 10, 100][[1]]] (* Amiram Eldar, Feb 07 2022 *)

-cos((1+sqrt(5))/2) \\ Charles R Greathouse IV, May 13 2019

Equals 1/A139349. - Amiram Eldar, Feb 07 2022

Edited by N. J. A. Sloane, Dec 11 2008

A144749 Decimal expansion of the golden ratio powered to itself.

Original entry on oeis.org

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

Offset: 1

R. J. Mathar, Sep 20 2008

See A092134 for the continued fraction of this value, phi^phi, where phi = (sqrt(5)+1)/2 = A001622. - M. F. Hasler, Oct 08 2014

			Equals 2.178457567937599147372545702871245851807043301693254611347781924...

G. C. Greubel, Table of n, a(n) for n = 1..10000
Index entries for transcendental numbers.

Cf. A001622, A104457, A098317, A094214, A139339, A139340, A144713.

RealDigits[N[GoldenRatio^GoldenRatio,200]] (* Vladimir Joseph Stephan Orlovsky, May 27 2010 *)

(t=(sqrt(5)+1)/2)^t \\ Use \p99 to get 99 digits; digits(%\.1^99) for the sequence of digits. - M. F. Hasler, Oct 08 2014

numerical_approx(golden_ratio^golden_ratio, digits=120) # G. C. Greubel, Jun 16 2022

Equals A001622^A001622.

A004937 a(n) = round(n*phi^2), where phi is the golden ratio, A001622.

Original entry on oeis.org

0, 3, 5, 8, 10, 13, 16, 18, 21, 24, 26, 29, 31, 34, 37, 39, 42, 45, 47, 50, 52, 55, 58, 60, 63, 65, 68, 71, 73, 76, 79, 81, 84, 86, 89, 92, 94, 97, 99, 102, 105, 107, 110, 113, 115, 118, 120, 123, 126, 128, 131, 134, 136, 139, 141, 144, 147, 149, 152, 154, 157

Offset: 0

N. J. A. Sloane

nonn

Amiram Eldar, Table of n, a(n) for n = 0..10000
Benoit Cloitre and Jeffrey Shallit, Some Fibonacci-Related Sequences, arXiv:2312.11706 [math.CO], 2023.

Cf. A001622, A104457.

Cf. A004938 - A004955, A007067.

[Round((3+Sqrt(5))*n/2): n in [0..80]]; // G. C. Greubel, Sep 13 2023

a[n_] := Round[n*GoldenRatio^2]; Array[a, 50, 0] (* Amiram Eldar, Jun 17 2022 *)

a(n)=round(n*(sqrt(5)+3)/2) \\ Charles R Greathouse IV, Aug 28 2016

[round(golden_ratio^2*n) for n in range(81)] # G. C. Greubel, Sep 13 2023

cp's OEIS Frontend

A139342 Decimal expansion of e^(-(1+sqrt(5))/2).

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A094885 Decimal expansion of phi*e, where phi = (1 + sqrt(5))/2.

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A202543 Decimal expansion of the number x satisfying e^(x/2) - e^(-x/2) = 1.

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A200135 Decimal expansion of the negated value of the digamma function at 1/5.

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A377805 Decimal expansion of the volume of a snub dodecahedron with unit edge length.

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A026273 a(n) = least k such that s(k) = n, where s = A026272.

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A139345 Decimal expansion of sine of the golden ratio. That is, the decimal expansion of sin((1+sqrt(5))/2).

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