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 1-7 of 7 results.

A248279 Egyptian fraction representation of sqrt(54) (A010507) using a greedy function.

Original entry on oeis.org

7, 3, 67, 4751, 25076431, 1253373011645810, 9187269148593176940086772749458, 498651977464932900685397060435928260390239175775532045711576034, 321776209073611476881274134051635561805771857820185011672099181310492331070886792488196910194328794077954530415887963244506932
Offset: 0

Views

Author

Robert G. Wilson v, Oct 04 2014

Keywords

Crossrefs

Egyptian fraction representations of the square roots: A006487, A224231, A248235-A248322.
Egyptian fraction representations of the cube roots: A129702, A132480-A132574.

Programs

  • Mathematica
    Egyptian[nbr_] := Block[{lst = {IntegerPart[nbr]}, cons = N[ FractionalPart[ nbr], 2^20], denom, iter = 8}, While[ iter > 0, denom = Ceiling[ 1/cons]; AppendTo[ lst, denom]; cons -= 1/denom; iter--]; lst]; Egyptian[ Sqrt[ 54]]

A010140 Continued fraction for sqrt(54).

Original entry on oeis.org

7, 2, 1, 6, 1, 2, 14, 2, 1, 6, 1, 2, 14, 2, 1, 6, 1, 2, 14, 2, 1, 6, 1, 2, 14, 2, 1, 6, 1, 2, 14, 2, 1, 6, 1, 2, 14, 2, 1, 6, 1, 2, 14, 2, 1, 6, 1, 2, 14, 2, 1, 6, 1, 2, 14, 2, 1, 6, 1, 2, 14, 2, 1, 6, 1, 2, 14, 2, 1, 6, 1, 2, 14, 2, 1
Offset: 0

Views

Author

Keywords

Examples

			7.348469228349534294591852224... = 7 + 1/(2 + 1/(1 + 1/(6 + 1/(1 + ...)))). - _Harry J. Smith_, Jun 06 2009
		

Crossrefs

Cf. A010507 Decimal expansion. - Harry J. Smith, Jun 06 2009

Programs

  • Mathematica
    ContinuedFraction[Sqrt[54],300] (* Vladimir Joseph Stephan Orlovsky, Mar 07 2011 *)
  • PARI
    { allocatemem(932245000); default(realprecision, 21000); x=contfrac(sqrt(54)); for (n=0, 20000, write("b010140.txt", n, " ", x[n+1])); } \\ Harry J. Smith, Jun 06 2009

A386739 Decimal expansion of the volume of a sphenocorona with unit edges.

Original entry on oeis.org

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

Views

Author

Paolo Xausa, Aug 01 2025

Keywords

Comments

The sphenocorona is Johnson solid J_86.

Examples

			1.5153516399764065597284793124718129048228695068...
		

Crossrefs

Cf. A010482 (surface area - 2), A178809 (surface area + 4).

Programs

  • Mathematica
    First[RealDigits[Sqrt[1 + 3*Sqrt[3/2] + Sqrt[13 + Sqrt[54]]]/2, 10, 100]] (* or *)
    First[RealDigits[PolyhedronData["J86", "Volume"], 10, 100]]

Formula

Equals sqrt(1 + 3*sqrt(3/2) + sqrt(13 + 3*sqrt(6)))/2 = sqrt(1 + 3*A115754 + sqrt(13 + A010507))/2.
Equals A386740 - A020775.
Equals the largest real root of 1024*x^8 - 1024*x^6 - 3008*x^4 - 96*x^2 + 9.

A386740 Decimal expansion of the volume of an augmented sphenocorona with unit edges.

Original entry on oeis.org

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

Views

Author

Paolo Xausa, Aug 01 2025

Keywords

Comments

The augmented sphenocorona is Johnson solid J_87.

Examples

			1.7510539003719224011954274331734292512511481527...
		

Crossrefs

Cf. A010502 (surface area - 1).

Programs

  • Mathematica
    First[RealDigits[Sqrt[1 + 3*Sqrt[3/2] + Sqrt[13 + Sqrt[54]]]/2 + 1/Sqrt[18], 10, 100]] (* or *)
    First[RealDigits[PolyhedronData["J87", "Volume"], 10, 100]]

Formula

Equals sqrt(1 + 3*sqrt(3/2) + sqrt(13 + 3*sqrt(6)))/2 + 1/(3*sqrt(2)) = sqrt(1 + 3*A115754 + sqrt(13 + A010507))/2 + A020775.
Equals A386739 + A020775.
Equals the largest real root of 45137758519296*x^16 - 110336743047168*x^14 - 191069246324736*x^12 + 209269081571328*x^10 + 364547659290624*x^8 - 58793017190400*x^6 + 3306865979520*x^4 - 1275399855936*x^2 + 1439671249.

A041092 Numerators of continued fraction convergents to sqrt(54).

Original entry on oeis.org

7, 15, 22, 147, 169, 485, 6959, 14403, 21362, 142575, 163937, 470449, 6750223, 13970895, 20721118, 138297603, 159018721, 456335045, 6547709351, 13551753747, 20099463098, 134148532335, 154247995433
Offset: 0

Views

Author

Keywords

Crossrefs

Programs

  • Mathematica
    Numerator[Convergents[Sqrt[54],30]] (* Harvey P. Dale, Jul 18 2013 *)
    CoefficientList[Series[- (x^11 - 7 x^10 + 15 x^9 - 22 x^8 + 147 x^7 - 169 x^6 - 485 x^5 - 169 x^4 - 147 x^3 - 22 x^2 - 15 x - 7)/((x^4 - 10 x^2 + 1) (x^8 + 10 x^6 + 99 x^4 + 10 x^2 + 1)), {x, 0, 30}], x] (* Vincenzo Librandi, Oct 25 2013 *)

Formula

a(n) = 970*a(n-6)-a(n-12). G.f.: -(x^11-7*x^10+15*x^9-22*x^8+147*x^7-169*x^6-485*x^5-169*x^4-147*x^3-22*x^2-15*x-7)/((x^4-10*x^2+1)*(x^8+10*x^6+99*x^4+10*x^2+1)). [Colin Barker, Jul 18 2012]

A041093 Denominators of continued fraction convergents to sqrt(54).

Original entry on oeis.org

1, 2, 3, 20, 23, 66, 947, 1960, 2907, 19402, 22309, 64020, 918589, 1901198, 2819787, 18819920, 21639707, 62099334, 891030383, 1844160100, 2735190483, 18255302998, 20990493481, 60236289960, 864298552921, 1788833395802, 2653131948723, 17707625088140
Offset: 0

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Author

Keywords

Crossrefs

Programs

Formula

a(n) = 970*a(n-6)-a(n-12). G.f.: -(x^10-2*x^9+3*x^8-20*x^7+23*x^6-66*x^5-23*x^4-20*x^3-3*x^2-2*x-1)/((x^4-10*x^2+1)*(x^8+10*x^6+99*x^4+10*x^2+1)). [Colin Barker, Jul 18 2012]

A379531 Decimal expansion of (3*sqrt(6) - 7)*Pi/3.

Original entry on oeis.org

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

Views

Author

Stefano Spezia, Dec 24 2024

Keywords

Comments

Lower bound to the volume of the Meisser's tetrahedral analog of the Reuleaux triangle.

Examples

			0.3649161225950003501847169303738650723435020735...
		

References

  • G. D. Chakerian and H. Groemer, Convex bodies of constant width, Convexity and Its Applications, ed. P. M. Gruber and J. M. Wills, Birkhäuser, 1983, pp. 49-96; MR85f:52001.
  • Steven R. Finch, Mathematical Constants, Encyclopedia of Mathematics and its Applications, vol. 94, Cambridge University Press, 2003, Section 8.10, p. 514.

Crossrefs

Programs

  • Mathematica
    RealDigits[(3Sqrt[6]-7)Pi/3,10,100][[1]]
Showing 1-7 of 7 results.