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 1-5 of 5 results.

A259624 Strictly increasing list of F - 1, F, and F + 1, where F = A000045, the Fibonacci numbers.

Original entry on oeis.org

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 12, 13, 14, 20, 21, 22, 33, 34, 35, 54, 55, 56, 88, 89, 90, 143, 144, 145, 232, 233, 234, 376, 377, 378, 609, 610, 611, 986, 987, 988, 1596, 1597, 1598, 2583, 2584, 2585, 4180, 4181, 4182, 6764, 6765, 6766, 10945, 10946, 10947
Offset: 1

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Author

Keywords

Crossrefs

Programs

  • Mathematica
    Union[# - 1, #, # + 1] &[Fibonacci[Range[50]]]
    CoefficientList[Series[-((x (1+x) (1+x+x^2+x^4) (1+x+2 x^2+x^3+x^4+x^5))/((1+x+x^2) (-1+x^3+x^6))),{x,0,60}],x] (* or *) LinearRecurrence[{-1,-1,1,1,1,1,1,1},{0,1,2,3,4,5,6,7,8,9,12,13},60] (* Harvey P. Dale, Nov 21 2024 *)

Formula

G.f.: -((x (1 + x) (1 + x + x^2 + x^4) (1 + x + 2 x^2 + x^3 + x^4 + x^5))/((1 + x + x^2) (-1 + x^3 + x^6))).

A259626 List of numbers L and L + 1, where L = A000032, the Lucas numbers, sorted into increasing order and duplicates removed.

Original entry on oeis.org

1, 2, 3, 4, 5, 7, 8, 11, 12, 18, 19, 29, 30, 47, 48, 76, 77, 123, 124, 199, 200, 322, 323, 521, 522, 843, 844, 1364, 1365, 2207, 2208, 3571, 3572, 5778, 5779, 9349, 9350, 15127, 15128, 24476, 24477, 39603, 39604, 64079, 64080, 103682, 103683, 167761, 167762
Offset: 1

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Author

Keywords

Crossrefs

Programs

  • Mathematica
    Union[#, # + 1] &[LucasL[Range[50]]]

Formula

G.f.: -((-1 - 2 x - x^2 + x^4 + x^5 + x^6 + x^7 + x^8)/((-1 + x) (1 + x) (-1 + x^2 + x^4)))

A259627 List of numbers L - 1, L, and L+1, where L = A000032, the Lucas numbers, sorted into increasing order and duplicates removed.

Original entry on oeis.org

0, 1, 2, 3, 4, 5, 6, 7, 8, 10, 11, 12, 17, 18, 19, 28, 29, 30, 46, 47, 48, 75, 76, 77, 122, 123, 124, 198, 199, 200, 321, 322, 323, 520, 521, 522, 842, 843, 844, 1363, 1364, 1365, 2206, 2207, 2208, 3570, 3571, 3572, 5777, 5778, 5779, 9348, 9349, 9350, 15126
Offset: 1

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Author

Keywords

Crossrefs

Programs

  • Mathematica
    Union[# - 1, #, # + 1] &[LucasL[Range[50]]]

Formula

G.f.: -((x (1 + x) (1 + x^2) (1 + 2 x + 3 x^2 + 2 x^3 + 2 x^4 + 2 x^5 +
2 x^6))/((1 + x + x^2) (-1 + x^3 + x^6)))

A259625 List of numbers L - 1 and L, where L = A000032, the Lucas numbers, sorted into increasing order and duplicates removed.

Original entry on oeis.org

0, 1, 2, 3, 4, 6, 7, 10, 11, 17, 18, 28, 29, 46, 47, 75, 76, 122, 123, 198, 199, 321, 322, 520, 521, 842, 843, 1363, 1364, 2206, 2207, 3570, 3571, 5777, 5778, 9348, 9349, 15126, 15127, 24475, 24476, 39602, 39603, 64078, 64079, 103681, 103682, 167760, 167761
Offset: 1

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Author

Keywords

Crossrefs

Programs

  • Mathematica
    Union[#, # - 1] &[LucasL[Range[50]]]

Formula

G.f.: -((x (-1 - 2 x - x^2 + x^5 + x^6 + x^7))/((-1 + x) (1 + x) (-1 + x^2 + x^4)))

A375274 Decimal expansion of the asymptotic density of the exponentially Fibonacci numbers (A115063).

Original entry on oeis.org

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

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Author

Amiram Eldar, Aug 09 2024

Keywords

Comments

This constant was apparently first calculated by Juan Arias-de-Reyna and Peter J. C. Moses in 2015 (see A115063).

Examples

			0.94433590506406332448057313775666880561463458322202...
		

Crossrefs

Programs

  • Mathematica
    $MaxExtraPrecision = m = 500; em = 16; f[x_] := Log[(1 - x) * (1 + Sum[x^Fibonacci[e], {e, 2, em}])]; c = Rest[CoefficientList[Series[f[x], {x, 0, m}], x] * Range[0, m]]; RealDigits[Exp[NSum[Indexed[c, k]*PrimeZetaP[k]/k, {k, 2, m}, NSumTerms -> m, WorkingPrecision -> m]], 10, 105][[1]]
  • PARI
    c(imax) = prodeulerrat((1-1/p)*(1 + sum(i = 2, imax, 1/p^fibonacci(i))));
    f(prec) = {default(realprecision, prec); my(k = 2, c1 = 0, c2 = c(k)); while(c1 != c2, k++; c1 = c2; c2 = c(k)); c1;}
    f(120)

Formula

Equals Product_{p prime} (1 + Sum_{i>=2} (u(i) - u(i-1))/p^i), where u(i) = A010056(i) is the characteristic function of the Fibonacci numbers (A000045) (first formula at A115063).
Equals Product_{p prime} (1 + Sum_{i>=4} (-1)^(i+1)/p^A259623(i)).
Equals Product_{p prime} ((1 - 1/p) * (1 + Sum_{i>=2} 1/p^Fibonacci(i))).
Showing 1-5 of 5 results.